http://en.wikipedia.org/wiki/Avatar_ (computing)

An avatar reflects user’s personality so when choosing an avatar remember: it will influence the way other users will see you. Some avatars can provoke irritation or rejection, and most people will transfer these emotions on the attitude towards you. So, there are some recommendations:

1. Your avatar must not be too big. The size of more than 150х150 px often corrupts forum design. Optimal size is 100х100.

2. Your avatar must not weigh much, because one forum page may turn to be quite expensive for some users. Optimal weight is 5-10 Kbyte.

3. If you avatar is animated it must not flicker too often. If it is not animated it must not be a mishmash of bright colors.

4. Avoid dirty inscriptions on avatars. Some users think it’s cool but it only shows your childishness and immaturity.

5. Avoid sexual images. If you are not a member of adult forum then this only means that you have problems with sex.

Maximal size (Kbytes) for uploaded avatars: 150 Kb
Maximal dimensions (Pixels) for uploaded avatars: 140x140Px

In the Control Panel in Users – Avatar Management (Main » Users » Avatars) you can select the default sets from which users will be able to choose their avatars. To disable a set (sets) remove the corresponding checkmarks.

You can also create your own avatar collections. Just follow the steps below:

• Create a folder named "ava" in the File Manager (letters in low case).
  
• Upload folders with avatars to the "ava" folder by means of any FTP client (a separate folder for each set). A set must contain not more than 100 avatars.
  

Here is how it looks:

For a Guest:

For users with avatars:

For users without avatars: