Everything you mark in a book is collected in one place: the Comments panel, on the right of the reader toolbar. Its subtitle counts what you have — "24 in this textbook".
Filtering
Two rows of filters:
All · Notes · Marks — "Notes" is anything you wrote words on, including a note attached to a highlight. "Marks" is everything else.
A chip per kind you actually have — Highlight, Underline, Strikeout, Squiggly, Note — each with its own count. Kinds you have never used are not offered.
Reading the list
Cards are grouped under the section they belong to, in the order they appear in the book, and each card shows the passage rendered as the mark you made it with — a blue highlight looks blue, an underline is underlined. Below it sit your notes, each dated, each editable in place.
Anything we cannot place in the book falls into a group called Unplaced rather than disappearing.
Jumping back to the page
Three ways, all doing the same thing: tap the card, press the arrow on its header, or use the ⋯ menu → Go to highlight. If the mark is in another chapter the reader navigates there and waits for it to be painted before it stops.
The ⋯ menu is also where Delete lives.
Adding to a mark later
A card with no note yet offers Add a note… right there. You do not have to find the passage again to write on it.
If the panel is empty it says so: "No comments yet. Select text in the reader to highlight it or add a note."
