I find the following line in /etc/shadow on our three Red Hat
Why is the password entry set to '!!' rather than '*'? If the shadow(5)
man page is correct, either will not allow logins (since it must be 13 to
24 characters long to be decrypted), but it still appears wrong.
Thank you for your time.
this is what adduser uses as a disable-flag. It works fine and is correct.