When you see a shaft flex marked L/A or R/S it means this is a combination flex shaft that can be made into either the L flex (Ladies) or A flex (Seniors) or the R flex for Regular men's flex and S for Stiff men's flex. You need to follow the trimming instructions to trim these shafts to play the flex you want them to be.
I am assuming you might be seeing the F on UST Mamiya shafts where they will use F1, F2, F3, F4 & F5 to denote the flexes of their shafts. The letters translate into the following flexes.
F1 = L flex (Ladies)
F2 = A flex (Seniors)
F3 = R flex (Regular Men's)
F4 = S flex (Stiff Men's)
F5 = X flex ( Extra Stiff Men's)
If you see just an F for flex it could mean a Firm Flex which is generally a shaft that will play between an Men's Regular and Stiff flex.
Date published: 2016-07-06