Visibility

Visibility refers to what can be seen by a player or NPC while a game is running. It is impacted by the PVS, but the two are not mutually inclusive.

Risk of Confusion:Visability^[sic], as coined in the Worldcraft 2.0 changelog, refers to what is seen by VIS. Stuff such as func_detail can block visibility without blocking visability. For more information, see VIS optimization.