1. If you have more than 500 posts, don't bother asking.
The reason for this is because we respect user IDs. You build a reputation here based on your username through your posts and post count. See TL's 10 Commandments.
2. Check if your name exists using http://www.teamliquid.net/forum/profile.php?user=NAME
(replace NAME with the username you want to change to)
Your request will be ignored if the username already exists. The burden is on you to check if the name exists. If you failed to do your research about existing names, then you might have to wait another month (and you might go over 500 posts by then). A good solution would be to put several alternatives, like please change my name to X, otherwise Y, otherwise Z.
3. TL reserves the right to change your name or refuse name changes for certain reasons.
If you changed your name already, you won't be able to do it again, so consider carefully. We don't allow advertising in usernames, and we generally don't like oBnoXiOuS capital letters or offensive names. We don't like ALLCAPS either. A good rule is, if your name would distract from the clarity of the forum, we won't let you have it.
4. We're no longer accepting changes for clan tags only. Put your team in your signature or profile.
5. This thread is checked once every month, near the end of the month.
6. Changing your name will result in loss of all Liquipedia edits contributed under your old name, as well as loss of permissions and coins. If you're a frequent wiki editor, do not change your name.
Please do not bump or PM mods about this. It will be done, don't worry and be patient.