In reply to The Pylon King:
> so where do V grades come in then?
V grades are for use only by Americans, in America. Or Australians, in Australia. To understand V grades, it's best to convert them to font grades, as in this article.
If you spot a V anywhere else, it's probably just an abbreviation of "velocity". You may have seen "V2 5c" or "V3 6a" in the BMC guidebooks, but as most people know, these are not grades, but formulas used to calculate how fast you must move your limbs in order to reach the top of the boulder.