John Grubb
The notation on OS Opendata Streetmap for "Petertavy Great Common" appears to be an error. Ditto Langstone Moor just north of this note. OS Landranger and Outdoor Leisure maps, as well as local almanacs, do not show these two names here but do show them in their correct locations north-west of here, just inside the Merrivale range boundary. OS Opendata Streetview also shows them inside the range boundary (i.e. possibly some sort of copy n' paste error at OS HQ). I have consequently deleted the notation in OSM at this note location.