B787 flight crew reported a confusing clearance revision via cpdlc led to a track deviation.

Attributes
ACN	1618371
Time
Date	201902
Local Time Of Day	1801-2400
Place
Locale Reference	KZAK.ARTCC
State Reference	HI
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B787 Dreamliner Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 211 Flight Crew Total 2727 Flight Crew Type 1669
Person 2
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 204 Flight Crew Total 8835 Flight Crew Type 1710
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types Flight Deck / Cabin / Aircraft Event Other / Unknown

Narrative:

Approximately 20NM from waypoint; we received a reroute clearance due to military activity in the area. The clearance uploaded into the FMC and was interpreted by first officer (first officer) and myself to fly direct to teryy; direct to [remainder of the route.] we both read and confirmed with each other before executing the route. I then proceeded to go direct to teryy. After the completion of the turn towards teryy; kzak sent a message 'confirm next waypoint.' I used the report page of the ATC page and said we were direct to teryy. Kzak uploaded a new clearance that similar to the previous clearance except at the end of the message it read; 'you were cleared dct terry after 20n160e. For my clarity you are now cleared dct terry.' we accepted the new clearance and proceeded direct teryy. First officer and I went over the original clearance and we did see the line 'at n20e160 cleared route clearance destination:zzzzvia. Todirect. Teryy[remainder of the route]the 'at n20e160 cleared route clearance' line was separated from the main body of the new clearance which caused us to miss the part of the message that we were supposed to fly directly to teryy after n20e160.

Original NASA ASRS Text

Title: B787 flight crew reported a confusing clearance revision via CPDLC led to a track deviation.

Narrative: Approximately 20NM from waypoint; we received a reroute clearance due to military activity in the area. The clearance uploaded into the FMC and was interpreted by FO (First Officer) and myself to fly Direct to TERYY; Direct to [remainder of the route.] We both read and confirmed with each other before executing the route. I then proceeded to go direct to TERYY. After the completion of the turn towards TERYY; KZAK sent a message 'Confirm Next Waypoint.' I used the REPORT page of the ATC page and said we were Direct to TERYY. KZAK uploaded a new clearance that similar to the previous clearance except at the end of the message it read; 'you were cleared DCT TERRY after 20N160E. For my clarity you are now cleared DCT TERRY.' We accepted the new clearance and proceeded direct TERYY. FO and I went over the original clearance and we did see the line 'At N20E160 cleared route clearance DEST:ZZZZVIA. TODIRECT. TERYY[Remainder of the route]The 'At N20E160 cleared route clearance' line was separated from the main body of the new clearance which caused us to miss the part of the message that we were supposed to fly directly to TERYY after N20E160.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.