How to make phone number a required field?

in CW 2 Site-Admins Helping Site-Admins

We would like to make the phone number a required field on the initial regsitration form.  It is fine if the member elects not to make the info public, however, email is not always a reliable way to reach a member.  We would like to collect a phone number so that a coordinator can contact a member, if needed.  I have set the collection setting for phone number field (user location) to "required" on the admin/user/settings page, but it still does not indicate that it is required (*) on the application and new member/user can submit the application without entering their phone number.  Is this being overridden in the php code somewhere?  Or ?  -Kelley