"M Q" CONUNDRUM

Does anyone know what this means? The stone is high on Bradup Moor, which stretches between Ilkley and Keighley. MQ - I've Googled and found nothing appropriate.

We were up on the moor for a little while this afternoon in search of the Rough-legged Buzzard, again. Someone else looking said it was probably over the hill on the Ilkley side of the moor, as they had a better class of rabbit that way. Anyway, we didn't see it. Not that I did much searching, more hunkered down in the car out of the wind, but it was lovely to get out of the house after a week of confinement and see a different view. Even if this MQ is now niggling me for an explanation.