if[Not]InRange=<action1>[,<action2>,...]
Tests if the current target is in range of the specified action. It is only applicable to actions which have explicit ranges specified in the tooltip. For example, Eviscerate is 5 yards, Shadowbolt is 30 yards (without talents). If the action has a minimum range (like Hunter shots), that applies as well, i.e. if the target is too close then ifInRange will be false.
Always use with if[Not]TargetAttackable since it will return true if the target is not a valid unit for the spell.
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.