A note marked “3” is not always the third note in an entire book. Numbering may restart by page, chapter, or section, and a copied fragment can lose the location that made the number useful.
When saving a note from an edition, keep the chapter or page reference and the note number together. Include the sentence that sends the reader to it when that connection is important.
Imagine two chapters each containing a note 3. A research card labelled only “note 3, translation issue” cannot tell you which discussion to reopen. “Chapter two, page 46, note 3” supplies a route that can be checked against the edition.
Digital pages add another complication: a screen’s third visible note may not carry the printed number three. Follow the actual marker instead of counting items in the browser.
If a hyperlink jumps to a note, test the return link too. It may lead to one of several references sharing the same note. Record the passage relevant to your argument rather than assuming every reference makes the same point.
A small amount of location information prevents a larger reading mistake later. The note’s number is an address within a system; preserving that system is part of preserving the evidence.
Editorial illustration from this site’s image library; not documentary evidence of the example or object discussed.