And if I remember correctly, the 'S' and 'P' numbers are pretty much the same as the 'M' numbers found in B2.1.
As to the other numbers in the Topic Title on this thread, the 'A' & 'F' numbers have to do with filler materials. Again, this is if I remember correctly, the 'A' is more after a composition rating while the 'F' numbers are more an ease of use category.
Different codes use the various numbers to reach various conditions within their scope. They have their reasons for why one uses 'F' while another uses 'A'. Just as the Group categories for steel in D1.1 don't necessarily match some of the groups found in B2.1 or in other codes. The lists differ according to purpose within the particular code.
Have a Great Day, Brent