I have recieved a request by a customer to construct a patch cable consisting of RJ-12 mod plugs on each end per spec.In all my years in this field I have never came accross the term RJ-12(aside from the usual RJ stuff).The spec sheet (Cisco) tels me this will be a 6P6C utlizing only 3 of the pins.Now my assumption is this is going to be a standard RJ-11(telephone)with 6P6C in place,and the term"RJ-12" is just a technical description of the mod plug.Please iterate.Thanks.