A bookmark covered in marks can benefit from one clear next action.
Choose the mark you need next.
Write one reason beside its location.
Move other questions into separate notes without claiming they are resolved.
Invented example: next: p.54, compare the two descriptions of the coat.
TabMap for iPhone and iPad: manually mark the page, choose Keep, Felt, Clue or Discuss, and add an optional private note. One complete book map is free; no app account required.
Developer disclosure: I build TabMap. AI assisted this original exercise; all examples are invented. You can also use paper. No measured reading benefit is claimed.