if[Not]Timer>XXs=<action>
The ifTimer criteria will first countdown XX seconds after initiating combat or changing targets before performing the action for the first time. It will then wait XXs before repeating the action again.
Also see ifLastUsed, everyXXs.
Legend
<item> is a placeholder and the entire string including <> should be replaced with the appropriate value. [text] means text is optional. {option1,option2,option3} means one of option1, option2 or option3 must be chosen. Batteries not included. UnitId can be any valid UnitId sequence as described in http://www.wowwiki.com/UnitId. Capitalization of UnitIds is not important. e.g. player, pet, target, targettarget. If the UnitId is optional, player is assumed.