Alice clues red to Bob, touching slot 2, slot 3, slot 4, and slot 5.
What slot is focused?
Is this a Play Clue or a Save Clue?
What card note does Bob write on the focused card?
Slot 3 is focused (i.e. the "new" card that was on chop).
Red 1 is played on the stacks and Bob already has a red 2 and a red 5. Thus, the focused red card can be either a red 3 or a red 4.
If it is a red 3, then this would be a Chop-Focus Delayed Play Clue through his own red 2. That is legal.
If it is a red 4, then it wouldn't make any sense, because red 4 is neither playable nor critical. (All clues must either be Play Clues or Save Clues.)
Thus, it must be a Chop-Focus Delayed Play Clue on the red 3.
Bob writes a card note of "red 3" on his slot 3 card.