Unique Characters Rule
The Unique Characters rule rejects passwords that do not contain a minimum number of unique characters. For example, the password "aaaaaaaa" only contains one unique character (a), whereas "mypassword" contains nine unique characters (mypasword). Increasing the number of unique characters in a password increases password strength by avoiding repetitive sequences that are easily guessed. The Unique Characters rule is case sensitive, so "LoOpHole" contains seven unique characters (LoOpHle).
Select the Unique characters check box to enable the Unique Characters rule.
Select the minimum number of unique characters that passwords must contain from the drop-down list.