yeah literally it means "position on the card", I had my wife (from Colombia) look at it and she agreed, it is either catalog number, or what page in the catalog the paint is on... she felt it was the catalog number...
anyway... the names of the paints wont match Mitch, what's more important is one, the equivalency chart does give you a better idea what you are looking for, and two even though the names don't match the FS number should correspond to a number on the Vallejo chart...
i.e you look up Non specular sea blue.. it's not on the vallejo chart, so you go to google and type something like FS number ,and the name of the paint... it should bring it up... there are some charts out there, maybe type in 'FS chart' and see if it gives you the FS number, then look it up on the Vallejo site...
if you dont have a Vallejo dealer near you, Gunze is a good paint, as well as the MM series of acryilics... maybe you can find one of those! Sharkskin lives in Brooklyn I believe, so maybe he might have an idea of what's around ya!
Good luck!!