HOWTO..

Change CTCP Version reply

1. Make X-Chat hide the version and allow a custom reply.

Server -> Hide Version

or

/set irc_hide_version on

(Both of these sets 'prefs.hidever')

2. Set the reply you want.

Settings -> Lists -> CTCP Replies

Add or modify VERSION to read 'nctcp %s foo' where 'foo' is the reply you want.