explain an XXX in more detail

Lib/sgmllib.py

@@ -246,6 +246,9 @@ class SGMLParser(markupbase.ParserBase):
             self.__starttag_text = rawdata[start_pos:match.end(1) + 1]
             return k
         # XXX The following should skip matching quotes (' or ")
+        # As a shortcut way to exit, this isn't so bad, but shouldn't
+        # be used to locate the actual end of the start tag since the
+        # < or > characters may be embedded in an attribute value.
         match = endbracket.search(rawdata, i+1)
         if not match:
             return -1