Whether the browser transmits it or not (I didn't test that, since it matters little here) doesn't impact whether the browser chooses to keep it around after the redirect nor whether it manages to actually keep it around in a useful manner. "Both browsers" ultimately fail.

But thanks for the term of art. I've previously looked for such and seen others look for such, all unsuccessfully. Though I had no problem finding it just now by searching for html rfc and then searching RFC 1866 for "#".