Issue #17902: Clarify doc of ElementTree.iterparse and IncrementalParser
Based on patch by Aaron Oakley
diff --git a/Doc/library/xml.etree.elementtree.rst b/Doc/library/xml.etree.elementtree.rst
index d0bfed0..c0cc683 100644
--- a/Doc/library/xml.etree.elementtree.rst
+++ b/Doc/library/xml.etree.elementtree.rst
@@ -416,7 +416,8 @@
and ``"end-ns"`` (the "ns" events are used to get detailed namespace
information). If *events* is omitted, only ``"end"`` events are reported.
*parser* is an optional parser instance. If not given, the standard
- :class:`XMLParser` parser is used. Returns an :term:`iterator` providing
+ :class:`XMLParser` parser is used. *parser* can only use the default
+ :class:`TreeBuilder` as a target. Returns an :term:`iterator` providing
``(event, elem)`` pairs.
Note that while :func:`iterparse` builds the tree incrementally, it issues
@@ -880,7 +881,7 @@
events are used to get detailed namespace information). If *events* is
omitted, only ``"end"`` events are reported. *parser* is an optional
parser instance. If not given, the standard :class:`XMLParser` parser is
- used.
+ used. *parser* can only use the default :class:`TreeBuilder` as a target.
.. method:: data_received(data)