Specific Requirements for Input on Customized User fields

Just a brief Feature Request for the Custom User Fields option for Admins (located in admin/customize/user_fields )

Would love to see the ability to set additional requirements on customized user fields. For example:

  1. Number – Required input to be a number
  2. Text – Required Input to be Text and not a number
  3. Length – Set a minimum or maximum character input for a given field
  4. Special Character Requirement – Allowed/Not allowed. Also would be useful to enforce a required secondary email address or other such item for some specific circumstances.

Thanks guys!