Upgrade fonttools to 4.4.2

Test: None
Change-Id: Id79232063c76c53c135d91bd37cd963b7711ec96
diff --git a/.travis.yml b/.travis.yml
index cf0f424..5f98e3b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,5 @@
 language: python
-python: 3.5
+python: 3.6
 
 env:
   global:
@@ -16,9 +16,6 @@
 
 matrix:
   fast_finish: true
-  exclude:
-    # Exclude the default Python 3.6 build
-    - python: 3.6
   include:
     - python: 3.6
       env:
diff --git a/Lib/fontTools/__init__.py b/Lib/fontTools/__init__.py
index 8636e78..955c1f4 100644
--- a/Lib/fontTools/__init__.py
+++ b/Lib/fontTools/__init__.py
@@ -4,6 +4,6 @@
 
 log = logging.getLogger(__name__)
 
-version = __version__ = "4.4.1"
+version = __version__ = "4.4.2"
 
 __all__ = ["version", "log", "configLogger"]
diff --git a/Lib/fontTools/feaLib/error.py b/Lib/fontTools/feaLib/error.py
index 82a7dec..66c6c6e 100644
--- a/Lib/fontTools/feaLib/error.py
+++ b/Lib/fontTools/feaLib/error.py
@@ -9,10 +9,18 @@
         message = Exception.__str__(self)
         if self.location:
             path, line, column = self.location
-            return "%s:%d:%d: %s" % (path, line, column, message)
+            return f"{path}:{line}:{column}: {message}"
         else:
             return message
 
 
 class IncludedFeaNotFound(FeatureLibError):
-    pass
+    def __str__(self):
+        assert self.location is not None
+
+        message = (
+            "The following feature file should be included but cannot be found: "
+            f"{Exception.__str__(self)}"
+        )
+        path, line, column = self.location
+        return f"{path}:{line}:{column}: {message}"
diff --git a/Lib/fontTools/misc/psCharStrings.py b/Lib/fontTools/misc/psCharStrings.py
index abb2647..b894653 100644
--- a/Lib/fontTools/misc/psCharStrings.py
+++ b/Lib/fontTools/misc/psCharStrings.py
@@ -417,7 +417,6 @@
 			self.numRegions = self.private.getNumRegions()
 		numBlends = self.pop()
 		numOps = numBlends * (self.numRegions + 1)
-		blendArgs = self.operandStack[-numOps:]
 		del self.operandStack[-(numOps-numBlends):] # Leave the default operands on the stack.
 
 	def op_vsindex(self, index):
diff --git a/Lib/fontTools/ttLib/tables/otConverters.py b/Lib/fontTools/ttLib/tables/otConverters.py
index 43aa31b..6f02050 100644
--- a/Lib/fontTools/ttLib/tables/otConverters.py
+++ b/Lib/fontTools/ttLib/tables/otConverters.py
@@ -1569,6 +1569,19 @@
 	def xmlRead(self, attrs, content, font):
 		return safeEval(attrs["value"])
 
+class LookupFlag(UShort):
+	def xmlWrite(self, xmlWriter, font, value, name, attrs):
+		xmlWriter.simpletag(name, attrs + [("value", value)])
+		flags = []
+		if value & 0x01: flags.append("rightToLeft")
+		if value & 0x02: flags.append("ignoreBaseGlyphs")
+		if value & 0x04: flags.append("ignoreLigatures")
+		if value & 0x08: flags.append("ignoreMarks")
+		if value & 0x10: flags.append("useMarkFilteringSet")
+		if value & 0xff00: flags.append("markAttachmentType[%i]" % (value >> 8))
+		if flags:
+			xmlWriter.comment(" ".join(flags))
+		xmlWriter.newline()
 
 converterMapping = {
 	# type		class
@@ -1595,6 +1608,7 @@
 	"DeltaValue":	DeltaValue,
 	"VarIdxMapValue":	VarIdxMapValue,
 	"VarDataValue":	VarDataValue,
+	"LookupFlag": LookupFlag,
 
 	# AAT
 	"CIDGlyphMap":	CIDGlyphMap,
diff --git a/Lib/fontTools/ttLib/tables/otData.py b/Lib/fontTools/ttLib/tables/otData.py
index 23bfd8d..1fa9156 100755
--- a/Lib/fontTools/ttLib/tables/otData.py
+++ b/Lib/fontTools/ttLib/tables/otData.py
@@ -87,7 +87,7 @@
 
 	('Lookup', [
 		('uint16', 'LookupType', None, None, 'Different enumerations for GSUB and GPOS'),
-		('uint16', 'LookupFlag', None, None, 'Lookup qualifiers'),
+		('LookupFlag', 'LookupFlag', None, None, 'Lookup qualifiers'),
 		('uint16', 'SubTableCount', None, None, 'Number of SubTables for this lookup'),
 		('Offset', 'SubTable', 'SubTableCount', 0, 'Array of offsets to SubTables-from beginning of Lookup table'),
 		('uint16', 'MarkFilteringSet', None, 'LookupFlag & 0x0010', 'If set, indicates that the lookup table structure is followed by a MarkFilteringSet field. The layout engine skips over all mark glyphs not in the mark filtering set indicated.'),
diff --git a/Lib/fonttools.egg-info/PKG-INFO b/Lib/fonttools.egg-info/PKG-INFO
index a0c831b..592ccf9 100644
--- a/Lib/fonttools.egg-info/PKG-INFO
+++ b/Lib/fonttools.egg-info/PKG-INFO
@@ -1,6 +1,6 @@
 Metadata-Version: 2.1
 Name: fonttools
-Version: 4.4.1
+Version: 4.4.2
 Summary: Tools to manipulate font files
 Home-page: http://github.com/fonttools/fonttools
 Author: Just van Rossum
@@ -414,6 +414,13 @@
         Changelog
         ~~~~~~~~~
         
+        4.4.2 (released 2020-03-12)
+        ---------------------------
+        
+        - [ttx] Annotate ``LookupFlag`` in XML dump with comment explaining what bits
+          are set and what they mean (#1850).
+        - [feaLib] Added more descriptive message to ``IncludedFeaNotFound`` error (#1842).
+        
         4.4.1 (released 2020-02-26)
         ---------------------------
         
@@ -1992,12 +1999,12 @@
 Classifier: Topic :: Multimedia :: Graphics :: Graphics Conversion
 Requires-Python: >=3.6
 Provides-Extra: ufo
-Provides-Extra: lxml
-Provides-Extra: woff
-Provides-Extra: unicode
-Provides-Extra: graphite
 Provides-Extra: interpolatable
 Provides-Extra: plot
+Provides-Extra: graphite
+Provides-Extra: unicode
 Provides-Extra: symfont
-Provides-Extra: type1
 Provides-Extra: all
+Provides-Extra: woff
+Provides-Extra: type1
+Provides-Extra: lxml
diff --git a/METADATA b/METADATA
index 7d1a15e..192735c 100644
--- a/METADATA
+++ b/METADATA
@@ -7,12 +7,12 @@
   }
   url {
     type: ARCHIVE
-    value: "https://github.com/fonttools/fonttools/releases/download/4.4.1/fonttools-4.4.1.zip"
+    value: "https://github.com/fonttools/fonttools/releases/download/4.4.2/fonttools-4.4.2.zip"
   }
-  version: "4.4.1"
+  version: "4.4.2"
   last_upgrade_date {
     year: 2020
-    month: 2
-    day: 26
+    month: 3
+    day: 12
   }
 }
diff --git a/NEWS.rst b/NEWS.rst
index 7fc3e1d..b56ed4e 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -1,3 +1,10 @@
+4.4.2 (released 2020-03-12)
+---------------------------
+
+- [ttx] Annotate ``LookupFlag`` in XML dump with comment explaining what bits
+  are set and what they mean (#1850).
+- [feaLib] Added more descriptive message to ``IncludedFeaNotFound`` error (#1842).
+
 4.4.1 (released 2020-02-26)
 ---------------------------
 
diff --git a/PKG-INFO b/PKG-INFO
index a0c831b..592ccf9 100644
--- a/PKG-INFO
+++ b/PKG-INFO
@@ -1,6 +1,6 @@
 Metadata-Version: 2.1
 Name: fonttools
-Version: 4.4.1
+Version: 4.4.2
 Summary: Tools to manipulate font files
 Home-page: http://github.com/fonttools/fonttools
 Author: Just van Rossum
@@ -414,6 +414,13 @@
         Changelog
         ~~~~~~~~~
         
+        4.4.2 (released 2020-03-12)
+        ---------------------------
+        
+        - [ttx] Annotate ``LookupFlag`` in XML dump with comment explaining what bits
+          are set and what they mean (#1850).
+        - [feaLib] Added more descriptive message to ``IncludedFeaNotFound`` error (#1842).
+        
         4.4.1 (released 2020-02-26)
         ---------------------------
         
@@ -1992,12 +1999,12 @@
 Classifier: Topic :: Multimedia :: Graphics :: Graphics Conversion
 Requires-Python: >=3.6
 Provides-Extra: ufo
-Provides-Extra: lxml
-Provides-Extra: woff
-Provides-Extra: unicode
-Provides-Extra: graphite
 Provides-Extra: interpolatable
 Provides-Extra: plot
+Provides-Extra: graphite
+Provides-Extra: unicode
 Provides-Extra: symfont
-Provides-Extra: type1
 Provides-Extra: all
+Provides-Extra: woff
+Provides-Extra: type1
+Provides-Extra: lxml
diff --git a/Tests/feaLib/data/lookupflag.ttx b/Tests/feaLib/data/lookupflag.ttx
index 52a09b8..82f1945 100644
--- a/Tests/feaLib/data/lookupflag.ttx
+++ b/Tests/feaLib/data/lookupflag.ttx
@@ -91,7 +91,7 @@
       <!-- LookupCount=22 -->
       <Lookup index="0">
         <LookupType value="1"/>
-        <LookupFlag value="1"/>
+        <LookupFlag value="1"/><!-- rightToLeft -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -103,7 +103,7 @@
       </Lookup>
       <Lookup index="1">
         <LookupType value="1"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -115,7 +115,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="1"/>
-        <LookupFlag value="4"/>
+        <LookupFlag value="4"/><!-- ignoreLigatures -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -127,7 +127,7 @@
       </Lookup>
       <Lookup index="3">
         <LookupType value="1"/>
-        <LookupFlag value="7"/>
+        <LookupFlag value="7"/><!-- rightToLeft ignoreBaseGlyphs ignoreLigatures -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -139,7 +139,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="1"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -151,7 +151,7 @@
       </Lookup>
       <Lookup index="5">
         <LookupType value="1"/>
-        <LookupFlag value="256"/>
+        <LookupFlag value="256"/><!-- markAttachmentType[1] -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -163,7 +163,7 @@
       </Lookup>
       <Lookup index="6">
         <LookupType value="1"/>
-        <LookupFlag value="512"/>
+        <LookupFlag value="512"/><!-- markAttachmentType[2] -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -175,7 +175,7 @@
       </Lookup>
       <Lookup index="7">
         <LookupType value="1"/>
-        <LookupFlag value="260"/>
+        <LookupFlag value="260"/><!-- ignoreLigatures markAttachmentType[1] -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -187,7 +187,7 @@
       </Lookup>
       <Lookup index="8">
         <LookupType value="1"/>
-        <LookupFlag value="16"/>
+        <LookupFlag value="16"/><!-- useMarkFilteringSet -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -200,7 +200,7 @@
       </Lookup>
       <Lookup index="9">
         <LookupType value="1"/>
-        <LookupFlag value="16"/>
+        <LookupFlag value="16"/><!-- useMarkFilteringSet -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -213,7 +213,7 @@
       </Lookup>
       <Lookup index="10">
         <LookupType value="1"/>
-        <LookupFlag value="20"/>
+        <LookupFlag value="20"/><!-- ignoreLigatures useMarkFilteringSet -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -238,7 +238,7 @@
       </Lookup>
       <Lookup index="12">
         <LookupType value="1"/>
-        <LookupFlag value="16"/>
+        <LookupFlag value="16"/><!-- useMarkFilteringSet -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -251,7 +251,7 @@
       </Lookup>
       <Lookup index="13">
         <LookupType value="1"/>
-        <LookupFlag value="768"/>
+        <LookupFlag value="768"/><!-- markAttachmentType[3] -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -263,7 +263,7 @@
       </Lookup>
       <Lookup index="14">
         <LookupType value="1"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -275,7 +275,7 @@
       </Lookup>
       <Lookup index="15">
         <LookupType value="1"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -311,7 +311,7 @@
       </Lookup>
       <Lookup index="18">
         <LookupType value="1"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -323,7 +323,7 @@
       </Lookup>
       <Lookup index="19">
         <LookupType value="1"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
@@ -347,7 +347,7 @@
       </Lookup>
       <Lookup index="21">
         <LookupType value="1"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage>
diff --git a/Tests/feaLib/data/spec5fi2.ttx b/Tests/feaLib/data/spec5fi2.ttx
index 0842cf9..6485c34 100644
--- a/Tests/feaLib/data/spec5fi2.ttx
+++ b/Tests/feaLib/data/spec5fi2.ttx
@@ -31,7 +31,7 @@
       <!-- LookupCount=2 -->
       <Lookup index="0">
         <LookupType value="6"/>
-        <LookupFlag value="7"/>
+        <LookupFlag value="7"/><!-- rightToLeft ignoreBaseGlyphs ignoreLigatures -->
         <!-- SubTableCount=1 -->
         <ChainContextSubst index="0" Format="3">
           <!-- BacktrackGlyphCount=1 -->
@@ -54,7 +54,7 @@
       </Lookup>
       <Lookup index="1">
         <LookupType value="1"/>
-        <LookupFlag value="7"/>
+        <LookupFlag value="7"/><!-- rightToLeft ignoreBaseGlyphs ignoreLigatures -->
         <!-- SubTableCount=1 -->
         <SingleSubst index="0">
           <Substitution in="d" out="d.alt"/>
diff --git a/Tests/feaLib/lexer_test.py b/Tests/feaLib/lexer_test.py
index fa3f0ea..3837801 100644
--- a/Tests/feaLib/lexer_test.py
+++ b/Tests/feaLib/lexer_test.py
@@ -178,7 +178,9 @@
     def test_include_missing_file(self):
         lexer = IncludingLexer(self.getpath("include/includemissingfile.fea"))
         self.assertRaisesRegex(IncludedFeaNotFound,
-                               "includemissingfile.fea:1:8: missingfile.fea",
+                               "includemissingfile.fea:1:8: The following feature file "
+                               "should be included but cannot be found: "
+                               "missingfile.fea",
                                lambda: list(lexer))
 
     def test_featurefilepath_None(self):
diff --git a/Tests/mtiLib/data/mti/chained-glyph.ttx.GPOS b/Tests/mtiLib/data/mti/chained-glyph.ttx.GPOS
index 811b1df..634c142 100644
--- a/Tests/mtiLib/data/mti/chained-glyph.ttx.GPOS
+++ b/Tests/mtiLib/data/mti/chained-glyph.ttx.GPOS
@@ -5,7 +5,7 @@
     <!-- LookupCount=2 -->
     <Lookup index="0">
       <LookupType value="8"/>
-      <LookupFlag value="512"/>
+      <LookupFlag value="512"/><!-- markAttachmentType[2] -->
       <!-- SubTableCount=1 -->
       <ChainContextPos index="0" Format="1">
         <Coverage Format="1">
diff --git a/Tests/mtiLib/data/mti/chained-glyph.ttx.GSUB b/Tests/mtiLib/data/mti/chained-glyph.ttx.GSUB
index 67aa902..52935c3 100644
--- a/Tests/mtiLib/data/mti/chained-glyph.ttx.GSUB
+++ b/Tests/mtiLib/data/mti/chained-glyph.ttx.GSUB
@@ -5,7 +5,7 @@
     <!-- LookupCount=2 -->
     <Lookup index="0">
       <LookupType value="6"/>
-      <LookupFlag value="512"/>
+      <LookupFlag value="512"/><!-- markAttachmentType[2] -->
       <!-- SubTableCount=1 -->
       <ChainContextSubst index="0" Format="1">
         <Coverage Format="1">
diff --git a/Tests/mtiLib/data/mti/gsubreversechanined.ttx.GSUB b/Tests/mtiLib/data/mti/gsubreversechanined.ttx.GSUB
index 62ba14f..38b3b75 100644
--- a/Tests/mtiLib/data/mti/gsubreversechanined.ttx.GSUB
+++ b/Tests/mtiLib/data/mti/gsubreversechanined.ttx.GSUB
@@ -5,7 +5,7 @@
     <!-- LookupCount=1 -->
     <Lookup index="0">
       <LookupType value="8"/>
-      <LookupFlag value="9"/>
+      <LookupFlag value="9"/><!-- rightToLeft ignoreMarks -->
       <!-- SubTableCount=3 -->
       <ReverseChainSingleSubst index="0" Format="1">
         <Coverage Format="2">
diff --git a/Tests/otlLib/builder_test.py b/Tests/otlLib/builder_test.py
index 3acf1c9..3675395 100644
--- a/Tests/otlLib/builder_test.py
+++ b/Tests/otlLib/builder_test.py
@@ -470,7 +470,7 @@
         assert getXML(lookup.toXML) == [
             "<Lookup>",
             '  <LookupType value="1"/>',
-            '  <LookupFlag value="7"/>',
+            '  <LookupFlag value="7"/><!-- rightToLeft ignoreBaseGlyphs ignoreLigatures -->',
             "  <!-- SubTableCount=2 -->",
             '  <SingleSubst index="0">',
             '    <Substitution in="one" out="two"/>',
@@ -524,7 +524,7 @@
         assert getXML(lookup.toXML) == [
             "<Lookup>",
             '  <LookupType value="1"/>',
-            '  <LookupFlag value="17"/>',
+            '  <LookupFlag value="17"/><!-- rightToLeft useMarkFilteringSet -->',
             "  <!-- SubTableCount=1 -->",
             '  <SingleSubst index="0">',
             '    <Substitution in="one" out="two"/>',
diff --git a/Tests/otlLib/data/gsub_51.ttx b/Tests/otlLib/data/gsub_51.ttx
index 280582c..f0aba65 100644
--- a/Tests/otlLib/data/gsub_51.ttx
+++ b/Tests/otlLib/data/gsub_51.ttx
@@ -105,7 +105,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/otlLib/data/gsub_52.ttx b/Tests/otlLib/data/gsub_52.ttx
index 189178c..03bd9ee 100644
--- a/Tests/otlLib/data/gsub_52.ttx
+++ b/Tests/otlLib/data/gsub_52.ttx
@@ -105,7 +105,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gpos1_1_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos1_1_lookupflag_f1.ttx.GPOS
index 93d3a05..0ed7d63 100644
--- a/Tests/ttLib/tables/data/aots/gpos1_1_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos1_1_lookupflag_f1.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="1"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos1_2_font2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos1_2_font2.ttx.GPOS
index 88257ac..ecd96b0 100644
--- a/Tests/ttLib/tables/data/aots/gpos1_2_font2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos1_2_font2.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="1"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <SinglePos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos2_1_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos2_1_lookupflag_f1.ttx.GPOS
index 06b0691..4924787 100644
--- a/Tests/ttLib/tables/data/aots/gpos2_1_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos2_1_lookupflag_f1.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos2_1_lookupflag_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos2_1_lookupflag_f2.ttx.GPOS
index 03e9f8b..97f64ab 100644
--- a/Tests/ttLib/tables/data/aots/gpos2_1_lookupflag_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos2_1_lookupflag_f2.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos2_2_font2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos2_2_font2.ttx.GPOS
index 7896be3..69abe30 100644
--- a/Tests/ttLib/tables/data/aots/gpos2_2_font2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos2_2_font2.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos2_2_font3.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos2_2_font3.ttx.GPOS
index 216a591..90771d3 100644
--- a/Tests/ttLib/tables/data/aots/gpos2_2_font3.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos2_2_font3.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos3_font2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos3_font2.ttx.GPOS
index 3ded3a7..0f94495 100644
--- a/Tests/ttLib/tables/data/aots/gpos3_font2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos3_font2.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="3"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <CursivePos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos3_font3.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos3_font3.ttx.GPOS
index e6a1c04..b3beb5c 100644
--- a/Tests/ttLib/tables/data/aots/gpos3_font3.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos3_font3.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="3"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <CursivePos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos4_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos4_lookupflag_f1.ttx.GPOS
index 744eaaa..f86f1d2 100644
--- a/Tests/ttLib/tables/data/aots/gpos4_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos4_lookupflag_f1.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <MarkBasePos index="0" Format="1">
           <MarkCoverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos4_lookupflag_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos4_lookupflag_f2.ttx.GPOS
index 7817336..9f1be15 100644
--- a/Tests/ttLib/tables/data/aots/gpos4_lookupflag_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos4_lookupflag_f2.ttx.GPOS
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <MarkBasePos index="0" Format="1">
           <MarkCoverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos5_font1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gpos5_font1.ttx.GSUB
index 85d3308..88d3f24 100644
--- a/Tests/ttLib/tables/data/aots/gpos5_font1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gpos5_font1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g30">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f1.ttx.GPOS
index ea85d9f..28832e4 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f2.ttx.GPOS
index bd176ba..80ae0c7 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f3.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f3.ttx.GPOS
index b189067..0958edf 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f3.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f3.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f4.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f4.ttx.GPOS
index f750652..8dc3f30 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f4.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_boundary_f4.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_lookupflag_f1.ttx.GPOS
index b07a9ba..dfde657 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_lookupflag_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="8"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ChainContextPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_multiple_subrules_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_multiple_subrules_f1.ttx.GPOS
index 09b5bd8..3a83808 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_multiple_subrules_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_multiple_subrules_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_multiple_subrules_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_multiple_subrules_f2.ttx.GPOS
index e8fb516..7eaf23e 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_multiple_subrules_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_multiple_subrules_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_next_glyph_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_next_glyph_f1.ttx.GPOS
index 1f7539e..597baba 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_next_glyph_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_next_glyph_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_simple_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_simple_f1.ttx.GPOS
index 1780fda..7f9b1c4 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_simple_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_simple_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_simple_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_simple_f2.ttx.GPOS
index c2d3411..70e0167 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_simple_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_simple_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining1_successive_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining1_successive_f1.ttx.GPOS
index 3960d8a..eadac06 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining1_successive_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining1_successive_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f1.ttx.GPOS
index fe06077..adcca5c 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f2.ttx.GPOS
index c529371..5108ddc 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f3.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f3.ttx.GPOS
index fa55cf1..de44a35 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f3.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f3.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f4.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f4.ttx.GPOS
index f943402..c1e2151 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f4.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_boundary_f4.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_lookupflag_f1.ttx.GPOS
index b26d93b..7c2bbae 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_lookupflag_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="8"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ChainContextPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_multiple_subrules_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_multiple_subrules_f1.ttx.GPOS
index 33399ba..b1c77b5 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_multiple_subrules_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_multiple_subrules_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_multiple_subrules_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_multiple_subrules_f2.ttx.GPOS
index dc10c2f..d098baf 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_multiple_subrules_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_multiple_subrules_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_next_glyph_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_next_glyph_f1.ttx.GPOS
index 9c18a9b..2bf7df5 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_next_glyph_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_next_glyph_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_simple_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_simple_f1.ttx.GPOS
index decc575..feb38f2 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_simple_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_simple_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_simple_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_simple_f2.ttx.GPOS
index a35678d..a4d3497 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_simple_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_simple_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining2_successive_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining2_successive_f1.ttx.GPOS
index 6775e5b..1b64d37 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining2_successive_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining2_successive_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f1.ttx.GPOS
index c362427..0c5a58f 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f2.ttx.GPOS
index 7b27f90..064ceb7 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f3.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f3.ttx.GPOS
index 73df34c..297f182 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f3.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f3.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f4.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f4.ttx.GPOS
index 67bfc0e..bafd2d3 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f4.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_boundary_f4.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_lookupflag_f1.ttx.GPOS
index b12b665..8f33742 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_lookupflag_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="8"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ChainContextPos index="0" Format="3">
           <!-- BacktrackGlyphCount=2 -->
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_next_glyph_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_next_glyph_f1.ttx.GPOS
index d5b0c1f..ebb9f42 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_next_glyph_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_next_glyph_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_simple_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_simple_f1.ttx.GPOS
index b9b0ce5..a610025 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_simple_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_simple_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_simple_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_simple_f2.ttx.GPOS
index 6d023ec..8d4ab5b 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_simple_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_simple_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_chaining3_successive_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_chaining3_successive_f1.ttx.GPOS
index f7c85b6..d0e1009 100644
--- a/Tests/ttLib/tables/data/aots/gpos_chaining3_successive_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_chaining3_successive_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_boundary_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_boundary_f1.ttx.GPOS
index 662ae54..b085005 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_boundary_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_boundary_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_boundary_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_boundary_f2.ttx.GPOS
index 56a4f7b..c397c07 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_boundary_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_boundary_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_expansion_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_expansion_f1.ttx.GPOS
index 77d52eb..cb05449 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_expansion_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_expansion_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_lookupflag_f1.ttx.GPOS
index 2d5f796..ac299e5 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_lookupflag_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="7"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_lookupflag_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_lookupflag_f2.ttx.GPOS
index ef419ff..2571ad4 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_lookupflag_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_lookupflag_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="7"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_multiple_subrules_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_multiple_subrules_f1.ttx.GPOS
index 82750d5..cad6cd6 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_multiple_subrules_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_multiple_subrules_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_multiple_subrules_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_multiple_subrules_f2.ttx.GPOS
index 764703b..7fcedc9 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_multiple_subrules_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_multiple_subrules_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_next_glyph_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_next_glyph_f1.ttx.GPOS
index ac00f86..47c6d6c 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_next_glyph_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_next_glyph_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_simple_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_simple_f1.ttx.GPOS
index 031f56f..14b2e95 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_simple_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_simple_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_simple_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_simple_f2.ttx.GPOS
index bb3d01d..33523f5 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_simple_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_simple_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context1_successive_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context1_successive_f1.ttx.GPOS
index 2d17ca5..8188bdf 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context1_successive_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context1_successive_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_boundary_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_boundary_f1.ttx.GPOS
index b830138..ea71d01 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_boundary_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_boundary_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_boundary_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_boundary_f2.ttx.GPOS
index a48dc6a..c8067b0 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_boundary_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_boundary_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_classes_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_classes_f1.ttx.GPOS
index 7573e48..64f8092 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_classes_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_classes_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_classes_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_classes_f2.ttx.GPOS
index 4435c02..216ce46 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_classes_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_classes_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_expansion_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_expansion_f1.ttx.GPOS
index 584892f..6b3b5d0 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_expansion_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_expansion_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_lookupflag_f1.ttx.GPOS
index 99546b5..bf9cfba 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_lookupflag_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="7"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_lookupflag_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_lookupflag_f2.ttx.GPOS
index 4a0fcb8..810bab3 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_lookupflag_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_lookupflag_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="7"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_multiple_subrules_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_multiple_subrules_f1.ttx.GPOS
index d2f38c3..c906fe6 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_multiple_subrules_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_multiple_subrules_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_multiple_subrules_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_multiple_subrules_f2.ttx.GPOS
index e5d0a63..50f7743 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_multiple_subrules_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_multiple_subrules_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_next_glyph_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_next_glyph_f1.ttx.GPOS
index c171781..57e6c41 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_next_glyph_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_next_glyph_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_simple_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_simple_f1.ttx.GPOS
index 266f31b..b38575d 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_simple_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_simple_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_simple_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_simple_f2.ttx.GPOS
index 8001658..b2f467d 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_simple_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_simple_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context2_successive_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context2_successive_f1.ttx.GPOS
index 2de586f..b5f70e2 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context2_successive_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context2_successive_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context3_boundary_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context3_boundary_f1.ttx.GPOS
index fd85d19..19b685a 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context3_boundary_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context3_boundary_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context3_boundary_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context3_boundary_f2.ttx.GPOS
index bee96ff..bffcccb 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context3_boundary_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context3_boundary_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context3_lookupflag_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context3_lookupflag_f1.ttx.GPOS
index e9c854c..3cf82eb 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context3_lookupflag_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context3_lookupflag_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="7"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextPos index="0" Format="3">
           <!-- GlyphCount=3 -->
diff --git a/Tests/ttLib/tables/data/aots/gpos_context3_lookupflag_f2.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context3_lookupflag_f2.ttx.GPOS
index e2b4a23..e96abac 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context3_lookupflag_f2.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context3_lookupflag_f2.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
@@ -97,7 +97,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="7"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextPos index="0" Format="3">
           <!-- GlyphCount=3 -->
diff --git a/Tests/ttLib/tables/data/aots/gpos_context3_next_glyph_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context3_next_glyph_f1.ttx.GPOS
index 44ce072..049ea85 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context3_next_glyph_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context3_next_glyph_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context3_simple_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context3_simple_f1.ttx.GPOS
index c559a7d..b565dd3 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context3_simple_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context3_simple_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gpos_context3_successive_f1.ttx.GPOS b/Tests/ttLib/tables/data/aots/gpos_context3_successive_f1.ttx.GPOS
index 8ff7eea..201052d 100644
--- a/Tests/ttLib/tables/data/aots/gpos_context3_successive_f1.ttx.GPOS
+++ b/Tests/ttLib/tables/data/aots/gpos_context3_successive_f1.ttx.GPOS
@@ -72,7 +72,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gsub1_1_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub1_1_lookupflag_f1.ttx.GSUB
index ba7b68f..8b4839d 100644
--- a/Tests/ttLib/tables/data/aots/gsub1_1_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub1_1_lookupflag_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="1"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <SingleSubst index="0" Format="1">
           <Substitution in="g18" out="g23"/>
diff --git a/Tests/ttLib/tables/data/aots/gsub1_2_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub1_2_lookupflag_f1.ttx.GSUB
index 51bfbb1..bc4d20e 100644
--- a/Tests/ttLib/tables/data/aots/gsub1_2_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub1_2_lookupflag_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="1"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <SingleSubst index="0" Format="2">
           <Substitution in="g18" out="g22"/>
diff --git a/Tests/ttLib/tables/data/aots/gsub2_1_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub2_1_lookupflag_f1.ttx.GSUB
index 2c59793..d3f65be 100644
--- a/Tests/ttLib/tables/data/aots/gsub2_1_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub2_1_lookupflag_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <MultipleSubst index="0" Format="1">
           <Substitution in="g18" out="g20,g21"/>
diff --git a/Tests/ttLib/tables/data/aots/gsub3_1_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub3_1_lookupflag_f1.ttx.GSUB
index 63c53b4..43a5e85 100644
--- a/Tests/ttLib/tables/data/aots/gsub3_1_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub3_1_lookupflag_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="3"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <AlternateSubst index="0" Format="1">
           <AlternateSet glyph="g18">
diff --git a/Tests/ttLib/tables/data/aots/gsub4_1_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub4_1_lookupflag_f1.ttx.GSUB
index 0982ef6..f485610 100644
--- a/Tests/ttLib/tables/data/aots/gsub4_1_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub4_1_lookupflag_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g18">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f1.ttx.GSUB
index 49ed83d..1c808ab 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f2.ttx.GSUB
index 7790bf9..de223ab 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f3.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f3.ttx.GSUB
index c58e3d5..3b7ea53 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f3.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f3.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f4.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f4.ttx.GSUB
index 43a1181..e98f40f 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f4.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_boundary_f4.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_lookupflag_f1.ttx.GSUB
index e3bdf7f..6b31555 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_lookupflag_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="6"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ChainContextSubst index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_multiple_subrules_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_multiple_subrules_f1.ttx.GSUB
index a8ceb2b..fe8935d 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_multiple_subrules_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_multiple_subrules_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_multiple_subrules_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_multiple_subrules_f2.ttx.GSUB
index f73b4ec..623534f 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_multiple_subrules_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_multiple_subrules_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_next_glyph_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_next_glyph_f1.ttx.GSUB
index 3858160..b50bb4c 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_next_glyph_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_next_glyph_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_simple_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_simple_f1.ttx.GSUB
index d7dbd6b..62e93a8 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_simple_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_simple_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_simple_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_simple_f2.ttx.GSUB
index e97a6b1..fc4e2b5 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_simple_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_simple_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining1_successive_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining1_successive_f1.ttx.GSUB
index 146dd2a..6b416df 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining1_successive_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining1_successive_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f1.ttx.GSUB
index ecd0a6b..36f3742 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f2.ttx.GSUB
index 076cb30..ebaaa62 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f3.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f3.ttx.GSUB
index c6fc1dc..ad5efd5 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f3.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f3.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f4.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f4.ttx.GSUB
index 4221c6c..5ef2c8d 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f4.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_boundary_f4.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_lookupflag_f1.ttx.GSUB
index eaccba0..f54d484 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_lookupflag_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="6"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ChainContextSubst index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_multiple_subrules_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_multiple_subrules_f1.ttx.GSUB
index c0447c2..b972275 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_multiple_subrules_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_multiple_subrules_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_multiple_subrules_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_multiple_subrules_f2.ttx.GSUB
index 6067dfd..790b312 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_multiple_subrules_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_multiple_subrules_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_next_glyph_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_next_glyph_f1.ttx.GSUB
index f3dcb64..7743df5 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_next_glyph_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_next_glyph_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_simple_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_simple_f1.ttx.GSUB
index 7997e3a..7ba2ad6 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_simple_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_simple_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_simple_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_simple_f2.ttx.GSUB
index bd3645a..02c2e01 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_simple_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_simple_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining2_successive_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining2_successive_f1.ttx.GSUB
index fd6ead4..8bf87f6 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining2_successive_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining2_successive_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f1.ttx.GSUB
index 579d6ce..b1dcebd 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f2.ttx.GSUB
index 5098ceb..82502fd 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f3.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f3.ttx.GSUB
index 3d6b966..bc18856 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f3.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f3.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f4.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f4.ttx.GSUB
index 9cf6009..40090e6 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f4.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_boundary_f4.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_lookupflag_f1.ttx.GSUB
index 9cc951e..78957e4 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_lookupflag_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="6"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ChainContextSubst index="0" Format="3">
           <!-- BacktrackGlyphCount=2 -->
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_next_glyph_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_next_glyph_f1.ttx.GSUB
index 00ff357..eba78ce 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_next_glyph_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_next_glyph_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_simple_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_simple_f1.ttx.GSUB
index 6cbf5f9..d40f71b 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_simple_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_simple_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_simple_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_simple_f2.ttx.GSUB
index 65fea5d..9fe4e1d 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_simple_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_simple_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_chaining3_successive_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_chaining3_successive_f1.ttx.GSUB
index 6e8918f..4b7e83c 100644
--- a/Tests/ttLib/tables/data/aots/gsub_chaining3_successive_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_chaining3_successive_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_boundary_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_boundary_f1.ttx.GSUB
index 5ce2dbc..21ae346 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_boundary_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_boundary_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_boundary_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_boundary_f2.ttx.GSUB
index f4df5df..12fbc54 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_boundary_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_boundary_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_expansion_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_expansion_f1.ttx.GSUB
index e03d5c3..be11729 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_expansion_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_expansion_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_lookupflag_f1.ttx.GSUB
index 7f7dbae..5f11e62 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_lookupflag_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="5"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextSubst index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_lookupflag_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_lookupflag_f2.ttx.GSUB
index 921576c..6982c7d 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_lookupflag_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_lookupflag_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="5"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextSubst index="0" Format="1">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_multiple_subrules_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_multiple_subrules_f1.ttx.GSUB
index 3bcb882..324d2cf 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_multiple_subrules_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_multiple_subrules_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_multiple_subrules_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_multiple_subrules_f2.ttx.GSUB
index 04e9696..02b04f6 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_multiple_subrules_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_multiple_subrules_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_next_glyph_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_next_glyph_f1.ttx.GSUB
index 1276fb9..28a264f 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_next_glyph_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_next_glyph_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_simple_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_simple_f1.ttx.GSUB
index 4e135b5..902fdb8 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_simple_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_simple_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_simple_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_simple_f2.ttx.GSUB
index 787c216..20b5f8f 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_simple_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_simple_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context1_successive_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context1_successive_f1.ttx.GSUB
index e0b1c54..fae8018 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context1_successive_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context1_successive_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_boundary_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_boundary_f1.ttx.GSUB
index 705389b..f56bb80 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_boundary_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_boundary_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_boundary_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_boundary_f2.ttx.GSUB
index 3a35d50..450df06 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_boundary_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_boundary_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_classes_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_classes_f1.ttx.GSUB
index 6716203..aa906e6 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_classes_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_classes_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_classes_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_classes_f2.ttx.GSUB
index deeea52..067e839 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_classes_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_classes_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_expansion_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_expansion_f1.ttx.GSUB
index 3952840..04afe57 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_expansion_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_expansion_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_lookupflag_f1.ttx.GSUB
index 80a6237..48a8ec1 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_lookupflag_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="5"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextSubst index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_lookupflag_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_lookupflag_f2.ttx.GSUB
index 715a1cd..3d1fad8 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_lookupflag_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_lookupflag_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="5"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextSubst index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_multiple_subrules_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_multiple_subrules_f1.ttx.GSUB
index 827db06..60cb81c 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_multiple_subrules_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_multiple_subrules_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_multiple_subrules_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_multiple_subrules_f2.ttx.GSUB
index 83d6af5..3e0965c 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_multiple_subrules_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_multiple_subrules_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_next_glyph_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_next_glyph_f1.ttx.GSUB
index 09e9dc9..79227dc 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_next_glyph_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_next_glyph_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_simple_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_simple_f1.ttx.GSUB
index 6bc8a46..e188ea9 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_simple_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_simple_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_simple_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_simple_f2.ttx.GSUB
index f65bf4d..1eeef69 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_simple_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_simple_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context2_successive_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context2_successive_f1.ttx.GSUB
index 3c7e0f9..fb3a2f0 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context2_successive_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context2_successive_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context3_boundary_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context3_boundary_f1.ttx.GSUB
index 843e88d..4b5bedd 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context3_boundary_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context3_boundary_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context3_boundary_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context3_boundary_f2.ttx.GSUB
index cba8c31..ecc88ad 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context3_boundary_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context3_boundary_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context3_lookupflag_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context3_lookupflag_f1.ttx.GSUB
index d485a04..4882e5e 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context3_lookupflag_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context3_lookupflag_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="5"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextSubst index="0" Format="3">
           <!-- GlyphCount=3 -->
diff --git a/Tests/ttLib/tables/data/aots/gsub_context3_lookupflag_f2.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context3_lookupflag_f2.ttx.GSUB
index 016350f..ff671b0 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context3_lookupflag_f2.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context3_lookupflag_f2.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
@@ -76,7 +76,7 @@
       </Lookup>
       <Lookup index="4">
         <LookupType value="5"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <ContextSubst index="0" Format="3">
           <!-- GlyphCount=3 -->
diff --git a/Tests/ttLib/tables/data/aots/gsub_context3_next_glyph_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context3_next_glyph_f1.ttx.GSUB
index 10fcba5..5c7943d 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context3_next_glyph_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context3_next_glyph_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context3_simple_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context3_simple_f1.ttx.GSUB
index 93f4bdd..3008fff 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context3_simple_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context3_simple_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/gsub_context3_successive_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/gsub_context3_successive_f1.ttx.GSUB
index 73e3567..b5c336a 100644
--- a/Tests/ttLib/tables/data/aots/gsub_context3_successive_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/gsub_context3_successive_f1.ttx.GSUB
@@ -58,7 +58,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g21">
diff --git a/Tests/ttLib/tables/data/aots/lookupflag_ignore_attach_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/lookupflag_ignore_attach_f1.ttx.GSUB
index f8064cb..874ba00 100644
--- a/Tests/ttLib/tables/data/aots/lookupflag_ignore_attach_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/lookupflag_ignore_attach_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="512"/>
+        <LookupFlag value="512"/><!-- markAttachmentType[2] -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g11">
diff --git a/Tests/ttLib/tables/data/aots/lookupflag_ignore_base_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/lookupflag_ignore_base_f1.ttx.GSUB
index 0982ef6..f485610 100644
--- a/Tests/ttLib/tables/data/aots/lookupflag_ignore_base_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/lookupflag_ignore_base_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="2"/>
+        <LookupFlag value="2"/><!-- ignoreBaseGlyphs -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g18">
diff --git a/Tests/ttLib/tables/data/aots/lookupflag_ignore_combination_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/lookupflag_ignore_combination_f1.ttx.GSUB
index 95047b3..e257bd7 100644
--- a/Tests/ttLib/tables/data/aots/lookupflag_ignore_combination_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/lookupflag_ignore_combination_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="514"/>
+        <LookupFlag value="514"/><!-- ignoreBaseGlyphs markAttachmentType[2] -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g18">
diff --git a/Tests/ttLib/tables/data/aots/lookupflag_ignore_ligatures_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/lookupflag_ignore_ligatures_f1.ttx.GSUB
index 3bc1e8d..d270f3c 100644
--- a/Tests/ttLib/tables/data/aots/lookupflag_ignore_ligatures_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/lookupflag_ignore_ligatures_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="4"/>
+        <LookupFlag value="4"/><!-- ignoreLigatures -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g18">
diff --git a/Tests/ttLib/tables/data/aots/lookupflag_ignore_marks_f1.ttx.GSUB b/Tests/ttLib/tables/data/aots/lookupflag_ignore_marks_f1.ttx.GSUB
index 28b4682..3712c06 100644
--- a/Tests/ttLib/tables/data/aots/lookupflag_ignore_marks_f1.ttx.GSUB
+++ b/Tests/ttLib/tables/data/aots/lookupflag_ignore_marks_f1.ttx.GSUB
@@ -31,7 +31,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="4"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <LigatureSubst index="0" Format="1">
           <LigatureSet glyph="g18">
diff --git a/Tests/varLib/data/PartialInstancerTest2-VF.ttx b/Tests/varLib/data/PartialInstancerTest2-VF.ttx
index ca9231d..6caef1b 100644
--- a/Tests/varLib/data/PartialInstancerTest2-VF.ttx
+++ b/Tests/varLib/data/PartialInstancerTest2-VF.ttx
@@ -649,7 +649,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_kerning_merging/0.ttx b/Tests/varLib/data/master_kerning_merging/0.ttx
index 858f927..1bc52ae 100644
--- a/Tests/varLib/data/master_kerning_merging/0.ttx
+++ b/Tests/varLib/data/master_kerning_merging/0.ttx
@@ -263,7 +263,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_kerning_merging/1.ttx b/Tests/varLib/data/master_kerning_merging/1.ttx
index d60a708..ea7c353 100644
--- a/Tests/varLib/data/master_kerning_merging/1.ttx
+++ b/Tests/varLib/data/master_kerning_merging/1.ttx
@@ -257,7 +257,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_kerning_merging/2.ttx b/Tests/varLib/data/master_kerning_merging/2.ttx
index e01a7b1..caf4275 100644
--- a/Tests/varLib/data/master_kerning_merging/2.ttx
+++ b/Tests/varLib/data/master_kerning_merging/2.ttx
@@ -263,7 +263,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Bold.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Bold.ttx
index a752bc1..53e0dda 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Bold.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Bold.ttx
@@ -477,7 +477,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Condensed.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Condensed.ttx
index db0372a..9b64f61 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Condensed.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Condensed.ttx
@@ -483,7 +483,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedBold.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedBold.ttx
index 3313ce6..5412599 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedBold.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedBold.ttx
@@ -483,7 +483,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedLight.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedLight.ttx
index c83912b..4315c6c 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedLight.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedLight.ttx
@@ -483,7 +483,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedSemiBold.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedSemiBold.ttx
index 7b0c88f..526eb44 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedSemiBold.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-CondensedSemiBold.ttx
@@ -483,7 +483,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Light.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Light.ttx
index 0e84719..ddba5e4 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Light.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Light.ttx
@@ -483,7 +483,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Regular.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Regular.ttx
index 44848db..07f9c15 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Regular.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-Regular.ttx
@@ -477,7 +477,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-SemiBold.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-SemiBold.ttx
index 7e6a0b3..3674082 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-SemiBold.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily3-SemiBold.ttx
@@ -483,7 +483,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily4-Italic15.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily4-Italic15.ttx
index f7aa15f..6df0a83 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily4-Italic15.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily4-Italic15.ttx
@@ -624,7 +624,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="6"/>
-        <LookupFlag value="16"/>
+        <LookupFlag value="16"/><!-- useMarkFilteringSet -->
         <!-- SubTableCount=1 -->
         <MarkMarkPos index="0" Format="1">
           <Mark1Coverage Format="1">
diff --git a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily4-Regular.ttx b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily4-Regular.ttx
index 2e354b0..ff7a52d 100644
--- a/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily4-Regular.ttx
+++ b/Tests/varLib/data/master_ttx_interpolatable_ttf/TestFamily4-Regular.ttx
@@ -618,7 +618,7 @@
       </Lookup>
       <Lookup index="2">
         <LookupType value="6"/>
-        <LookupFlag value="16"/>
+        <LookupFlag value="16"/><!-- useMarkFilteringSet -->
         <!-- SubTableCount=1 -->
         <MarkMarkPos index="0" Format="1">
           <Mark1Coverage Format="1">
diff --git a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-100,100.ttx b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-100,100.ttx
index 56b5623..5e1107c 100644
--- a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-100,100.ttx
+++ b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-100,100.ttx
@@ -417,7 +417,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-100,62.5.ttx b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-100,62.5.ttx
index d220e15..146e863 100644
--- a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-100,62.5.ttx
+++ b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-100,62.5.ttx
@@ -417,7 +417,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-400,100.ttx b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-400,100.ttx
index b71369e..add86a6 100644
--- a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-400,100.ttx
+++ b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-400,100.ttx
@@ -411,7 +411,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-400,62.5.ttx b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-400,62.5.ttx
index 9db3e86..1405904 100644
--- a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-400,62.5.ttx
+++ b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-400,62.5.ttx
@@ -417,7 +417,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-900,100.ttx b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-900,100.ttx
index 6ae729b..e48936a 100644
--- a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-900,100.ttx
+++ b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-900,100.ttx
@@ -417,7 +417,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-900,62.5.ttx b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-900,62.5.ttx
index 7c923e4..62bd722 100644
--- a/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-900,62.5.ttx
+++ b/Tests/varLib/data/test_results/PartialInstancerTest2-VF-instance-900,62.5.ttx
@@ -417,7 +417,7 @@
       <!-- LookupCount=1 -->
       <Lookup index="0">
         <LookupType value="2"/>
-        <LookupFlag value="8"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
         <!-- SubTableCount=1 -->
         <PairPos index="0" Format="2">
           <Coverage Format="1">
diff --git a/setup.cfg b/setup.cfg
index 8df7230..3fae00e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 4.4.1
+current_version = 4.4.2
 commit = True
 tag = False
 tag_name = {new_version}
diff --git a/setup.py b/setup.py
index 469d798..7d43aeb 100755
--- a/setup.py
+++ b/setup.py
@@ -345,7 +345,7 @@
 
 setup(
 	name="fonttools",
-	version="4.4.1",
+	version="4.4.2",
 	description="Tools to manipulate font files",
 	author="Just van Rossum",
 	author_email="just@letterror.com",