Earlier quoted context omitted.
For me, HN handles votes using deep links, since I have JS disabled.
I’ve never tried it, but my understanding is when JS is disabled HN fires off a GET request (via a link) and returns a 204 to prevent browser navigation, right?
You can see votes appear on your network tab under the image tab instead of Fetch/XHR, even though their response return type is text/html -- interesting little hack, although I'm not quite sure why it's done this way instead of fetching since it already requires JS.