Avatar Guidelines
Avatars must not be any bigger than 100 x 100 pixels and 102400 bytes (100 KB).
Avatars must comply with the Guidelines of Behaviour.
Avatars may be moving but must not be overly flashing/annoying/distracting.

Signature Guidelines
Signatures must be no longer than 400 characters and no more than 4 lines in height.
Signatures must comply with the Guidelines of Behaviour.
Signatures must be no more than 150 pixels in height and no more than 500 pixels in length.
Signature may only be static images (non moving).