phone number validation is too restrictive/should be dropped

Currently, the phone number is being validated for conformity with US numbering scheme. There?s no way we can have a valid validation rule that would accept any (or even most) valid phone numbers world-wide.

Example: Polish institutions often use ?internal? phone numbers; we?d write ?555 12 34 wew. 678? to denote that one must call 5551234 to get to the institution?s automatic switchboard, and then press 678 to get routed to the person?s desk (?wew.? stands for ?wewn?trzny? == ?internal?). I think we should allow such notation.

Note: This is not an internationalisation/localisation issue ? you should be able to have my Polish mobile number in your CiviCRM no matter where you live and what your CiviCRM?s localisation settings are.