Temporary Profile
From Halopedia, the Halo wiki
Template:Realworld A temporary profile is used in Halo 3, for players or users that do not have created a profile and wish to play in a Multiplayer or Campaign game. When a player without a profile signs into a game, he/she will be asked if they would like to use a temporary profile.
Temporary profiles cannot be saved. When you receive a temporary profile, you are issued a random username. Examples are "Wort" and "Sparty".