Company manual.
After “V1” call, the Captain’s hand should be
removed from the thrust levers.
At 5 kts below V1, call, “V1.”
Most of the reject takeoff discussion is from the FCTM, but this paragraph is slipped in:
Since V1 is the maximum speed for initiating an RTO, the decision to stop
must be made prior to V1. To account for reaction time, V1 is called 5 kts
prior to the actual V1.
Most, if not all CAs remove their hand from the TLs at the V1 call.