In the Venedotian Code used in Gwynedd, the units of length were said to have been codified by Dyfnwal Moelmud but retained unchanged by Hywel Dda.
In measuring milk and its legal worth (teithi), disputes over the length of the inch used in the container were to be resolved by the width of the judge's thumb.
[2] The code notes that in some areas of Wales, the rod used to compute the Welsh acre (erw) was not reckoned from feet but taken to be "as long as the tallest man in the [tref], with his hand above his head".
[3] In the Venedotian Code used in Gwynedd, the basic field unit was the Welsh acre or erw, whose legal description—its breadth as far as a man can reach in either direction with an ox-goad as long as the long yoke (16 Welsh feet) and its length "thirty times that measure"[10][5]—is noted by Owen as ambiguous.
The 11th-century Bleddyn ap Cynfyn is also described as having changed the legal composition of the homestead for purposes of inheritance and so on, varying its size depending on the social status of the owner.