User blog comment:DaNASCAT/Introducing New Moderator Opportunities For Community Administration/@comment-2129700-20160125184612/@comment-24258073-20160125234623

It was only for one year, and depending on what wiki features were enabled, the moderator user group might not have been accessible on the said wikis.

Without the message walls and/or forum boards, the moderator user group was not available because either of those features needed to be enabled for users to get any benefit from having the moderator flag.