When you quit, you should be offered a prompt to enter the reason why, which will either be livelogged or appended to the “quit” death in the xlogfile.

If you quit while on the Astral Plane, your game creates a special type of bones file which only contains the details of your character and their possessions (minus a real Amulet of Yendor, with a fake one added).

When other players reach Astral, their games can load this file to create an NPC of your character replacing one of the generic player monsters on Astral.

A #ragequit command which quits the game without any confirmation. But it’s a non-autocompleting extended command, so you do have to type the whole word out.