Show a legend of your groups in the Who's Online and Recently Browsing widgets, sorted in the order you specify and linked to the search system. Handy so that people know what those group prefixes and suffixes mean.
You choose which groups appear in the legend, and the order they will appear in, with the plugin settings in the ACP. Group links will carry any group formatting (colors, etc.) you may have set. Clicking the entries in the legend takes users to a list of all members with that group designation.
This version is probably fine with 4.6.x but it's been awhile so try it and disable it if it doesn't work.
