The GDS themselves state that users are more likely to archive their own copies of PDF documents than HTML documents: "users are more likely to download a PDF a

The GDS themselves state that users are more likely to archive their own copies of PDF documents than HTML documents: "users are more likely to download a PDF and continue to refer to it and share it offline" Part of the reason may be that some browsers download PDFs for display in the user's native reader. Though, even in-browser PDF readers like Firefox on desktop have a toolbar with a prominent save button. The use of PDF is a signal to the user that the document can be saved.