bookmarks
World bookmark day?

Scanning?
Incredibles inspired?
They were attached to a string, along which a marker could be slid up and down to mark a precise level on the page. Attached to the marker was a rotating disk that could indicate the column (usually numbered one to four, indicating the two columns on the left-hand page, and the two columns on the right-hand page).
R. Emms • Rotating bookmark
Yes… this is it.
This is what I thought we need.
What is old now will become new again.
14th or early 15th century rotating bookmark from France
Considerations for safe bookmark usage
Bookmarks that do not damage the books that they are used in should be acid-free, thin, so they will not indent the pages they rest between, and include no dyes or decorative materials that might bleed into the book's paper, with flat, thin, gentle edges.
Bookmarks that do not damage the books that they are used in should be acid-free, thin, so they will not indent the pages they rest between, and include no dyes or decorative materials that might bleed into the book's paper, with flat, thin, gentle edges.
Bookmark
The first detached, and therefore collectible, bookmarkers began to appear in the 1850s. One of the first references to these is found in Mary Russell Mitford's Recollections of a Literary Life (1852): "I had no marker and the richly bound volume closed as if instinctively." Note the abbreviation of 'bookmarker' to 'marker'. The modern abbreviation... See more
Bookmark
The earliest existing bookmark dates from the 6th century AD and it is made of ornamented leather lined with vellum on the back and was attached with a leather strap to the cover of a Coptic codex (Codex A, MS 813 Chester Beatty Library, Dublin).[2] It was found near Sakkara, Egypt, under the ruins of the monastery Apa Jeremiah. Further earliest... See more
Bookmark

Should I take the level of precision further? Down to the word, or letter?
What could that look like?
