Part of the RTAW Rules and Regulations states that:
4. ... You agree not to post any copyrighted material unless the copyright is owned by you or by MASA, or permission for use has been obtained.
This applies to any copyright material, including images utilised as avatars.
It is recommended that users either use an image that they have generated themselves or one from the extensive avatar gallery now provided. Users can be asked to provide evidence of permission from the owner to use a particular image. If no permission has been obtained or the case for permission is unclear, then it needs to be changed. Remember that the rest of the RTAW Rules and Regulations apply to avatars, where appropriate, and any image it is deemed to be inappropriate will be removed.
Avatars can be edited via Profile, with a link provided on the top of every RTAW Forums page. The avatar gallery is accessible via the "Show gallery" button, just above the "Submit" button at the bottom of the page.
Images in Signatures
Also, a reminder that images are not allowed to be used in signatures on RTAW Forums. If you want to express some individuality, then either do that via text in the signature or the avatar selected.