This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
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.