Door

You can open, close, lock, or unlock (if you have an appropriate key) a door or a container.

You can open, close, lock, or unlock the door exits of the room by the exact name of the exit (e.g. > open gate), or by giving the direction of the exit (e.g. > open exit s). Secret exits have to be addressed by their exact name. Non-hidden exits can be addressed as simply 'exit'.

'> open stone' or '> open stone south' [or just 'open stone s']
'> open chest' or '> open 2.chest'

(if there's more than one to choose from)

Note that latched doors can be locked and unlocked without a key.

See also: Pick, Knock, Keyring, Lockpicks, Call