Cable TV Directional Coupler specifications - What SB means?
SB is just part of their component part number which seems to correlate with dB on the tap.

This is a 12dB tap is 8 dB stronger but main feedthru will be about 0.2 dB less

Different taps  are made for distributing signals to difference populations of users.

If all the clients are together within very (assumed low loss) cable length then an N-way equal splitter is used. But if distributed among many more than 12 clients then directional couplers are used to feed a drop (dB) then cary to next user.

A splitter is also the same as DC-3 which drops ~3.5dB splitting power in half. DC means Directional Coupler in this case.  So a DC-12 or DC-16 splits or "couples" or "taps" a small fraction of -N dB of the signal power, so normally the signal must be boosted at source by more than this in order to for a small sample tap to be dropped then sent to the next coupler.

Splitters are basically used "Star" topology and Directional Couplers for "daisy-chain" tapped topology.