Now, this may sound a bit odd or unnecessary, due to it's implication in-game, but...
What about forum groups or clubs? Many people make their identity in the community through the forum, and there are many "groups" of users who get together especially well and organize events together, so maybe it would be cool to have official groups. Maybe a maximum of 3 groups- 1 personal, one main roleplay and one other; and one can be made a "main group" and a tag customizable by the group founder would then appear on their profile.
Some pros I can think of:
-Would bring the community a bit closer, especially if Group Alliances were implemented along with it
-Make organization of community hosted parties easier
-May encourage people to become more active on the forum
-Art, preset or code groups could encourage more amazing creations and contributions
-Tags or public display of groups could add to a user's sense of identity or pride of their niche in the community