asme specs question 1

[bigmacben]

hello all, this is my first thread so i hope i have placed it in the right forum.
in ASMEI IX table QW/QB-422 under the spec no column you have different spec letters for example A, A/SA.
can you tell me what B/SB, stands for please,

 

[XL83NL]

ASTM A/ASME SA is for ferrous materials specs. this covers e.g. carbon, low-alloy and stainless steels
ASTM B/ASME SB is for nonferrous materials specs. this covers nickel, titanium and other (non-ferrous, hence the name) alloys