What is the etiquette for going to another plane?

[Daspolo]

One of my players is interested in casting plane shift and going to nirvana for the sake of recieving guidance on the destruction of a dangerous artifact the party just got. I am wondering what the rules are for going to nirvana, or perhaps other planes if he wants to. I assume the lawful planes will probably detain him if he tries to enter and he'll need to be cleared, and the chaotic realms will be largely free for alls. Is there anything more specific in the lore though?

[GM Rednal]

The upcoming Planar Adventures may talk about it, but probably won't be out in time for your game. If your player isn't specifying a set destination, one thing you can do is have some behind-the-scenes 'beacons' that Plane Shift tends to latch onto when set for a more-or-less random destination in an aligned plane. This would bring visitors straight to a receiving area where their issues can be handled.

[Claxon]

I'm not sure it's at all covered anywhere, but a knowledge planes check should probably tell him whatever you decide to go with. Ultimately the player probably shouldn't be surprised by anything that happens unless no one in the party has access to knowledge planes.