Idle

From MUME

When a player has been away from the game for a long enough time they will lapse into a state of semi-consciousness and fade away into the void.

These players are idle, and are identified by the word (Idle) next to their name in the who list. Idle players are able to see tells directed to them, however since they are away from the game for whatever reason they most likely will not return your tell.

Setting up your linkdrop can enable you to remain unidle.

See also: Void, Linkdrop