Hi

These are the special characters I know/heard of:
Code:
x           : password is in /etc/shadow
*,X         : invalid password
[empty]     : no password set. should be changed after first login by the user.
!           : redirection to /etc/security/passwd
!!          : (HP-UX) allow ssh, albeit invalid password, no rhosts, no direct login
NOLOGIN     : (HP-UX) allow ssh and rhosts, no direct login
An idea to explain what you observe: * denotes that the password is invalid.
If the field has an * and a password is required for user authentication,
the user cannot log in. In a few distros/flavours, they seem to interpret
this rule like the HP-UX (no login at all, except ssh (public key) if the (invalid)
password is provided by !!), others might allow access if some form of
authentication is provided, like via public-key.


Cheers.

/edit: for completeness, NOLOGIN added. Credits to roswell.