+INSTALL regexp-opt.el
+=====================
+
+Some T-gnus modules use the functions `regexp-opt', etc. That
+functions are defined in regexp-opt.el(c) in the recent Emacsen,
+however, Mule 2.3 does not contain it in the standard Lisp libraries.
+Copy the file contrib/regexp-opt.el to site-lisp directory (or any
+other directory), and byte-compile it as follows:
+
+ % cp -p contrib/regexp-opt.el /usr/local/share/mule/site-lisp
+ % cd /usr/local/share/mule/site-lisp/
+ % mule -batch -q -no-site-file -f batch-byte-compile regexp-opt.el
+
+