Specifying Impermissible Passwords
You can prevent users from choosing passwords that you do not want to allow. To prohibit the use of a password, enter it in table USR40. You can maintain table USR40 with Transaction SM30.
In USR40, you can specify impermissible passwords generically if you want. There are two wildcard characters:

123* in table USR40 prohibits any password that begins with the sequence "123."
*123* prohibits any password that contains the sequence "123."
AB? prohibits all passwords that begin with "AB" and have one additional character: "ABA", "ABB", "ABC" and so on.