Consider the idea of Absolute modes and relative modes--the relative mode being the one that starts on a given step of another scale, while the absolute mode would simply start on a given pitch. Absolute Dorian would start on C, relative dorian would start on the second step of a C scale.

As for the "10 commandment modes"--it kind of makes sense, since the modes tended to be named for the prayer melodies that the notes were in. I would guess that the names were no longer used after the 10 commandments stopped being part of the daily prayers.