The regions, with their names and numbering are taken from The Relative Hills of Britain by Alan Dawson.
The Clems, originally called the Yeamans of England & Wales or Yeomans, extend Yeaman's criterion of "an eminence which has an ascent of 100m all round, or, failing that, is at least 5km (walking distance) from any higher point on neighbouring hills" to England, Wales and the Isle of Man. The list was compiled by E D "Clem" Clements in 1993 and renamed after his death. We give all these hills plus a further 14 subsequently identified by Clem in 2004. For details please consult the Clems Change Register http://www.hills-database.co.uk/yeaman_changes.html..
Clem's list was the original source for the Humps of England and Wales.
(Clems appear as Class=Cm on this website)