Yes it's 10% for my Australian delivered version. So:
88 km/h indicated=> 80 km/h true (gps)
99...................90 true.
110.................100 true.
So now I ride at 88, 99, 110 etc. for respective speed zones...what's the point Mr Honda?
I considered getting one of those electronic pulse frequency modifiers to compensate, but have found that the odometer and trip meter function is accurate as it is. Tinkering for the speedo may very well screw the odometer.