Answer: marginalia

AnswerCrossword Clue
MARGINALIAReader's notes, at times
MARGINALIANotes in a book.
MARGINALIABook notes.
MARGINALIAReader's notes alongside the text
marginaliamarginal notes
marginalianotes in the margin of a book, manuscript, or letter.
marginaliaMarginal notes