Bukkit

This plugin supports users who inherit multiple groups. It can use this to include each group the player is in in the formatted chat message
To achieve this, an additional variable has been added. The “multigroup-format” property in the config file specifies what
the chat formatting for multiple groups looks like. Like “message-format” it can also contain characters, colour codes, and variables.
To enable multigroups, place the +groups tag anywhere in the message-format above.

Available variables:

+prefix – The prefix of each group to be showed
+suffix – The suffix of each group to be showed
+group – The name of the group to be showed

Example (Default):
multigroup-format: '[+prefix+group+suffix]’

Say the user was in three groups, Herp, Derp and Default. With the above config, anywhere that +groups was added to the
message-format property above would be replaced with “[Herp][Derp][Default]”.

PExChat also supports specifying in what order the groups should appear, via the use of tracks.