* docs/PROBLEMS: Mention that some PS based fonts can't be
handled correctly by FreeType.
diff --git a/docs/PROBLEMS b/docs/PROBLEMS
index fb0fee0..9b59896 100644
--- a/docs/PROBLEMS
+++ b/docs/PROBLEMS
@@ -4,6 +4,29 @@
----------------------------------------------------------------------
+Running Problems
+================
+
+
+* Some Type 1, Multiple Masters, and CID-keyed PostScript fonts aren't
+ handled correctly.
+
+-----
+
+Of course, there might be bugs in FreeType, but some fonts based on
+the PostScript format can't behandled indeed. The reason is that
+FreeType doesn't contain a full PostScript interpreter but applies
+pattern matching instead. In case a font doesn't follow the standard
+structure of the given font format, FreeType fails. A typical example
+is Adobe's `Optima' font family which contains extra code to switch
+between low and high resolution versions of the glyphs.
+
+It might be possible to patch FreeType in some situations, though.
+Please report failing fonts so that we investigate the problem and set
+up a list of such problematic fonts.
+
+----------------------------------------------------------------------
+
Compilation Problems
====================
@@ -50,3 +73,5 @@
----------------------------------------------------------------------
+
+--- end of PROBLEMS ---