There are already two lists on wiki which provide the ID's and regnames of all volunteers, wiki editors, forum mods, smiley makers & translators.
http://util.xat.com/wiki/index.php?title=Volunteers
http://util.xat.com/wiki/index.php?title=Translators
If anything, people should be made more aware of this, because this can prove legitimacy 100% - if a user claims to be user xxx, make sure their credentials (IDs, regnames etc) match up on the wiki, if they don't, report them! I don't believe volunteers need to start having special titles on the chat.