Intended to validate html5 form input of type=tel in internation E.164 format, to validate Dutch phone numbers for valid routes and length. Geographic (open number plan: subscriber number cannot start with 0,1 or 9), and non-geographic (closed number plan), 0800 and 090x numbers including 8/11 digit length checking. Not implemented are 14xxx style government numbers. This regex can be used in PBXes as part of a larger dial plan string to allow immediate dialing as soon as the correct number of digits has been entered. Replace \+ with your international dialing prefix.