Date: 202111
Local time of day: 0601-1200
Location: UAAA.Airport, FO
Aircraft: Widebody Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Taxi
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Troubleshooting; Situational Awareness; Other / Unknown; Confusion; Communication Breakdown; Workload
Second reporter function: Relief Pilot; Pilot Not Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Ground Event / Encounter Other / Unknown; Ground Incursion Runway
Detector: Person Flight Crew
When detected: Taxi
Result: General None Reported / Taken
Contributing factors: Procedure; Chart Or Publication; Environment - Non Weather Related; Airport
Primary problem: Ambiguous

Narrative: We were given the clearance to back-taxi on Runway 23R to hold short of Runway 23L/F holding point.  We taxied down 23R and turned onto Taxiway Foxtrot.  As we turned onto Taxiway F; there were two hold-short position lines close together.  We taxied past the first hold short line and stopped short of the second set of lines to hold-short in between the lines and physically clear of both runways.It was then we realized that the taxiway markings were not what we were expecting.  Because we were stopped (between both hold short lines) we were actually on both active runways simultaneously. When we turned onto Foxtrot taxiway from R-23R we should have held short of the first set of lines (the hold-short lines for R-23L).  This would have left us stopped on R-23R (an active runway). After a short discussion between the crew; we realized that the second set of hold-short lines would do the same thing exiting the parallel (R-23L) taxing toward R-23R.  I can never recall ever seeing hold-short lines reversed like this.  Incidentally; upon looking closely at the taxi diagram; all the taxiways between the parallel runways are marked this way. I feel these hold-short lines are very confusing and non-standard.Most airports in the world; where we fly; have parallel runways with a little segment on the taxiway that will allow us to clear the active runway and hold-short of the parallel runway. In ZZZZ; [another location;] the airplane will always be holding short of the other active parallel runway while on an active runway in order to comply with the airport signs and taxiway markings.In this instance there was no conflicting traffic either on the runways or on approach; but for other crews in the future that will not always be the case.  Tower did not mention the incursion and the flight continued uneventfully.  I recommend that these non-standard markings be highlighted in the station guide with a diagram highlighting these taxiways and their markings.


Second narrative: During taxi for takeoff R-23L we were given clearance to back taxi down R-23R and to hold short of R23L at holding point taxiway Foxtrot.  I was occupying the jump seat behind the Captain. The Before Takeoff checklist and briefing was completed while back taxiing down R-23R.  The FO was Pilot Flying for this flight and was taxiing and would perform the takeoff.  After turning onto taxiway Foxtrot; the aircraft was stopped and the crew (CA; FO and other Jump Seater) began to discuss the taxiway and hold short markings on Foxtrot. The short discussion centered around which of the 2 hold short lines they should have held short of.  During this discussion; clearance for takeoff was given.  The takeoff and remainder of the flight were uneventful. Unfortunately; from my vantage point (seatbelt fastened; behind the rest of the crew and on the opposite side of the aircraft from the turn onto taxiway Foxtrot) I was unable to view taxiway Foxtrot's markings.Based on my review of this incident and the EFB information available; I would recommend to change the wording and emphasis on the taxiway hold short markings which I believe are very non-standard. I admit that based on the language contained in my EFB 'Reference Charts Taxi Procedures' and the 'Hot Spots' information on Taxi Diagram. I still would not have understood what was being said even though these taxiways are labeled as 'Hot Spots'. When viewing the taxi 'Chart' it is not clear that there are 2 sets of hold short lines. Only when viewing the XYZ information do you see that there are 2 different hold lines and only when zooming into the chart as much as possible do these lines show the orientation of the 2 solid double lines and dashes lines. I recommend changing the Hotspot description to read 'HOT SPOTS 1 thru 6; Non-Standard holding positions. When holding short of the parallel active runway you must stop short of the first set of hold short lines and will be stopped on the runway designated for taxing/back taxi and will not be clear of it until passing the first set of hold short lines. Do not taxi past the first set of hold short lines until cleared onto the active runway for lineup or takeoff.'


Synopsis: Large Transport Captain and Relief First Officer reported; that while holding between the two parallel runways at UAAA airport; their large transport was obstructing both runways. The pilots say the taxi lines are non-standard.