docs/engine/reference/commandline/logout.md

redirect_from	description	keywords	title
/reference/commandline/logout/	The logout command description and usage	logout, docker, registry	docker logout

Usage:  docker logout [SERVER]

Log out from a Docker registry.
If no server is specified, the default is defined by the daemon.

Options:
      --help   Print usage

For example:

$ docker logout localhost:8080