The password field must be filled\&. The encrypted password consists of 13 to 24 characters from the 64 characters alphabet a thru z, A thru Z, 0 thru 9, \\\&. and /\&. Optionally it can start with a "$" character\&. This means the encrypted password was generated using another (not DES) algorithm\&. For example if it starts with "$1$" it means the MD5\-based algorithm was used\&.
The date of the last password change is given as the number of days since Jan 1, 1970\&. The password may not be changed again until the proper number of days have passed, and must be changed after the maximum number of days\&. If the minimum number of days required is greater than the maximum number of day allowed, this password may not be changed by the user\&.
An account is considered to be inactive and is disabled if the password is not changed within the specified number of days after the password expires\&. An account will also be disabled on the specified day regardless of other password expiration information\&.