An abreviation for the word "Alternative" meaning the type of music.

1. In music, short for Alternative.

2. In RPG, short for Alternate ID.

3. In MPD, short for alter or persona.

4. In keyboarding, the Alt key, located just to the left of the space bar.

5. In HTML, the alternative text attribute of the img tag.

In MMPORGS like MUDs, a reference to a player's supplementary--thus "alternative"--avatar/character. Not the player's primary character but one used for blowing off steam, avoiding a primary character's responsibilities, or exacting anonymous revenge on a player-character you dislike.