That reference only sets out specifications
for the various items included in SOLAS A or B packs, it doesn't specify which items are required for A as opposed to B packs.
Many of the items listed are not required for SOLAS B.
SOLAS A packs have, in addition to SOLAS B
Extra flares, water
line, can opener
Here's one link that sets out the actual contents (Canadian, so there are a few other things there as well):