The PASSWORD_FORMAL_CHECK function module can determine whether a string meets the current password rules.
PASSWORD_FORMAL_CHECK does not evaluate the following rules:
Password may not be changed to any of a user's last <n> passwords
The user can only change the password after correctly entering the old password.
A user can change his or her password only once a day.
At least <n> characters in the new password must be different from the old password.
For an exact description of the sequence and the scope of the check, see the documentation for the function module. View the documentation with Function Builder (transaction SE37).