right rm ... as a 20-year veteran tape reader, I'd add:
a) mkt makers work reserve order flow into t&s 100-300 shares at a time vs big 10k blocks, to conceal their intent/size (for icebergs), when practical
b) during strong breakouts they can't do that and have to increase size to 1k+ share blocks
c) in tape reading I look for increasing volume in green prints/ask orders as seen in more block trades as price goes up
d) unless you're scalping large 3-5k+ size for tiny moves, L2 is not as useful as it once was; the tape is key