min special char in password specifies the minimum number of special characters for a password. Valid values are:
0 through 16 – the minimum number of special characters required for a password.
-1 – the password cannot contain special characters.
By default, this password complexity option is turned off and this check is not applied to passwords.
To set the minimum number of special characters in a password, enter:
sp_passwordpolicy 'set', 'min special char in password', number
