@ben To me it looks like it's the 2 >| characters, in a font that has a reduced height for | and breadth for >.

The only way to be sure is to check the godot source code (I would check if for you if I had the time to git clone the whole repo, as you can't see anything on github anymore without running proprietary JavaScript).

The easiest way to replicate it would be to take a screenshot of the character, crop it to size and remove the background and save to a png (too bad that'll only really work with HTML documentation, where you can inject a charter sized png wherever you want really).