A Person can also be tracked/linked by a Mobile Directory Number (MDN). This alternate identifier is sufficient in the short-term, but it is not an ideal long-term identification method because mobile numbers can be changed, returned, ported, and recycled.
Note: The MDN must be in e164 format, for example: +12195551234.A mobile number is required using e164 format. E.164 is the official format for all international phone numbers that includes a plus sign followed by the country code and phone number.
- U.S.: +1213-555-1234
- U.K.: +442135551234