Various magic items got bonuses on returning from other planes.

[Edi]

Possessing the item gives you an increased chance of being able to return from Inferno, Kokytos or the Void. E.g. Tome of the Lower Planes gives a 50% bonus on escaping from both Inferno and Kokytos and the Dimensional Rod gives a bonus to escaping from the Void.

[K]

Originally Posted by Edi

Possessing the item gives you an increased chance of being able to return from Inferno, Kokytos or the Void. E.g. Tome of the Lower Planes gives a 50% bonus on escaping from both Inferno and Kokytos and the Dimensional Rod gives a bonus to escaping from the Void.

But they always did that. I assume that this recent patch note would mean that something new has been added.