Forum users can no longer change their display name. (The name that appears to everyone when you post.) It's too confusing to keep track of who is who when people rename themselves all the time.
If you want your name changed for a valid reason, please PM me
(not the mods) and I can change it for you.
If you've changed your name since you signed up, your new name is still active. You just can't modify it yourself anymore.
In addition, once you reach 1000 posts (Commander), you can set a "custom title" for yourself that will appear under your name, in addition to your rank. This is just a small reward for those of you who've been here a while and contributed a lot.
You should be able to see this field above the box where you edit your signature. If you have 1000+ posts and can't see it, let me know!