Information
Defines the number of characters within a password which must be non-alphabetic.
In setting the minother attribute, it increases password complexity by enforcing the use of non-alphabetic characters in every user password.
Solution
In /etc/security/user set the default user stanza minother attribute to be greater than or equal to 3 :
chsec -f /etc/security/user -s default -a minother=3
This means that there must be at least 3 non-alphabetic characters within a password.