Between xchat-1.2.1, as distributed in 6.1, and xchat-1.4.0 from 6.2
all html files from /usr/doc/xchat-... disappeared. There are still
sgml sources there but there are not that useful for somebody without
a complement of tools. Dropping sgml instead (and leaving that in
sources, of course) would be actually preferrable.
This should be fixed in the next version.