I hate seeing posts by annoying pedants. But since no one else will volunteer, i guess it is my turn to be one.
I was surprised to find out recently that there was some difference in opinion between the French and the English over the appropriate dimensions of whole and half plates.
Apparently, Desire Van Monckhoven in 1863 determined that the proper dimensions of whole plate was 7-1/8" x 9-7/16" and half plate should be 5-3/8" x 7-1/8".
This is from "Traite general de photographie", 3rd edition, 1863 by way of Primitive Photography, the excellent calotype manual by Alan Greene.