Writing style: require Oxford commas
Currently the HIG has a section on writing style, but it's very short and has nothing to say on the topic of Oxford commas ("a, b, and C") vs. no Oxford commas ("a, b and c"). I'd like to simply require them always in GNOME UIs, since it improves readability, has no disadvantages and has become much more popular in the Internet age. When the comma is omitted, like I just did there in that previous sentence, the list looks less parallel and can be harder to read.
I don't think we want the HIG to grow into the Chicago Manual of Style or anywhere close to, but adding a just a few guidelines for the most common style choices would bring additional consistency to the user experience. In particular, I'd like to be able to reopen GNOME/gnome-software!650 (closed). ;)