-l, --lock This option is used to lock the password of specified account and it is available to root only. The locking is performed by rendering the encrypted password into an invalid string (by prefixing the encrypted string with an !). Note that the account is not fully locked - the user can still log in by other means of authentication such as the ssh public key authentication. Use chage -E 0 user command instead for full account locking.
-L, --lock Lock a user's password. This puts a '!' in front of the encrypted password, effectively disabling the password. You can't use this option with -p or -U.
Both options put a
! at the very beginning of the password in the shadow file.
usermod doesn't warn about not locking for other kinds of authentications if it's supposed to do the same?
Is there anything else to have consideration with when locking an account between this two options?