I've added usage guidance for the following tags in that list:
For questions related to special bloodlines (such as vampiric, draconic, etc) and gameplay or narrative features related to them.
For questions about the Inquisitor, a Pathfinder 1e divine class.
(All 16 questions in this tag are also Pathfinder 1e questions; we can update if/when there's another kind of Inquisitor people begin asking about)
for questions about specifics of using move actions, in games where that's a component of the action economy.
In the D&D and Pathfinder family of games, the Immediate Action is an action that takes place nearly-instantaneously. In the context of D&D 4e, this is in reference to immediate interrupts and reactions, which are triggered actions.
In D&D 4e, the use of immediate actions is exclusively in the form of reactive, triggered moves. For example, opportunity attacks are an immediate interrupt; so is timely dodge. I don't know if that's also the case in D&D 3.5e and Pathfinder 1e, but if so this description could be massively simplified.