ABC's and 123's

[nosnownogo!]

Can someone explain to me the ABC's and 123's of a Yamaha secondary?
Does it go from weakest to strongest A1,A2,A3,B1,B2,B3,C1,C2,C3 and can the secondary sping be install both ways or is there an up and down side?

This is on a 94 V-max. Thanks...