Shelf
Folders Shelf may write to
Shelf saves only into these folders and the folders inside them. Nothing else on this computer is touched.
Opening files
What a click on a file does. Reader renders notes, code and notebooks; Browser opens the file itself in a Chrome tab, as it would from disk (needs “Allow access to file URLs” for Desk). The right-click menu always offers both. Complete pages (.mhtml) always open in the browser.
Links
So the note still says something if the page changes or disappears. Only public pages can be fetched this way.