This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
number is a read-only property that indicates the phone number where to forward the calls.
var number = instanceOfMozMobileCFInfo.number;
Return a string.
Not part of any specification.