I'm happy to stand corrected. The letters on mine are stamped on the circular clamp, rather than the wire itself. A copy of Shimano instructions trumps my secondhand brakes!
That chart is lovely with it and those brake setter tools I can finally setup my brakes properly and then my brakes will never stop me again! :facepalm:
My thanks again to everybody and fluffy chicken for their helpful replies
Cheers
LF