A password must meet the following requirements:
Length. By default, a password must have at least six characters. Only the first eight characters are significant. (In other words, you can have a password that is longer than eight characters, but the system only checks the first eight.) Because the minimum length of a password can be changed by a system administrator, it may be different on your system.
Characters. A password must contain at least two letters (either upper- or lower-case) and at least one numeral or symbol such as @,#,%. For example, you can use dog#food or dog2food as a password, but you cannot use dogfood.
Not your login ID. A password cannot be the same as your login ID, nor can it be a rearrangement of the letters and characters of your login ID. (For the purpose of this criteria, upper and lower case letters are considered to be the same.) For example, if your login ID is Claire2 you cannot have e2clair as your password.
Different from old password. Your new password must differ from your old one by at least three characters. (For the purpose of this criterion, upper- and lower-case letters are considered to be the same.) For example, if your current password is Dog#fooD you can change it to dog#Meat but you cannot change it to daT#Food.