Cross (X) means – ignore, unimportant, already figured out

Tick means – done

/ or – in the margin means — attention

Circle (or cloud) means — doubtful, unsure, unclear, ambiguous

? means — no clue , or confusing, more than merely doubtful

! means — unusual, counter-intuitive, need to internalize

square means –  research, ask
5-pointed star (as on kids’ homework) means – Excellent

▲ ( U+25B2 ) means — important

▼ ( U+25BC ) means — less important

$ means — high monetary value