Widebody; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Training / Qualification; Confusion
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Company Policy; Manuals; Procedure
Proceeding direct to ENLON Intersection with clearance thereafter on UL602.  Logged on to London Center on CPDLC. Received message on CPDLC: 'Cleared to NATEB via route clearance; rest of route unchanged.' I accepted the clearance and pressed load to load the route. The loaded route had us going to TENDO Intersection then on to NATEB. First Officer noticed this and advised me that the clearance was to NATEB. I agreed and we entered direct to NATEB. [A few minutes later] London advised us that we were cleared to TENDO then NATEB. I responded that our CPDLC clearance had us direct to NATEB. We were then cleared direct to NATEB. No where in the body of the CPDLC message did it mention TENDO intersection. Is the  prompted loaded route the correct clearance or should the message from London have included TENDO in its description? Our training has not addressed any procedure regarding the load function on the ATC page in regards to the clearance.; i.e. When the load button is pressed; is that routing your actual clearance? On a related subject; the online CPDLC tutorial only works with a Windows computer and not on my Mac. Very frustrating.I suggest better CPDLC training.
[Report contains no additional information.]
An aircraft with CPDLC received a clearance direct a waypoint not on the original route; but after accepting the clearance; ATC asked them to verify they were going to a bypassed flight plan waypoint which confused the crew.