Demon/Devil Banishment and CoA

  • IRC discussion came up where I pointed out that years ago outside CoA, canon-wise (and cited an example of Drizzt banishing a named Balor Lord for 100 years), if a demon/devil is defeated on the Prime Material Plane, it's banished and can't return for a minimum of 100 years real-time.

    What I'm wanting to know is, is this something that's accepted and enforced on CoA where named demon/devil NPCs, when defeated, are banished for 100 years (pending, of course, some loophole).

    I believe this was used in the Kar'thax'alon plot years ago as well, if memory serves when he was repelled 1-2 time(s).

    Or is this something that's FOIG?