This forum is using Flarum. Here's a guide to the syntax markup used here:
https://discuss.flarum.org/d/2991-how-to-use-markdown-and-bbcodes/8
Of course most of this is done for you by the buttons in the editing toolbar below your post. But I thought it was a nice reference in case you want to do it yourself. And I learned a few things, like the fact that you can use three tildes instead of three backticks to start/end a block of code.
(I'm still digging into how we can get Flarum to add syntax coloring to our code blocks.)