This policy setting allows you to specify the type of password that users must create. If you enable this policy setting, ...

This policy setting allows you to specify the type of password that users must create.  If you enable this policy setting, then you can specify that passwords must be alphanumeric ("Strong"), a numeric PIN ("PIN"), or either type ("PIN or Strong").  If you disable this policy setting, users can set either an alphanumeric password or a numeric PIN.  If you do not configure this policy setting, then existing password-related settings on the device remain in effect.