|NOLOGIN(8)||System Management Commands||NOLOGIN(8)|
nologin - politely refuse a login
The nologin command displays a message that an account is not available and exits non-zero. It is intended as a replacement shell field for accounts that have been disabled.
To disable all logins, investigate nologin(5).
If SSH_ORIGINAL_COMMAND is populated it will be logged.
The nologin command appeared in BSD 4.4.