Also, Markdown doesn't support ``` fenced code blocks; that's a common misconception. I don't know which Markdown derivative originated them (maybe GFM?) but they ended up in CommonMark.
There isn't a single markdown. There are many different flavors, and all of them are markdown. Many include ``` (GitHub, Kdoc, pandoc, reddit, commonmark), especially as it allows you to specify the language if you want. I actually don't know if any tool I use that doesn't support them.
New Reddit (aka, Really Obnoxious Interface Reddit) uses that as well. Since Old Reddit is the only useable version of Reddit (IMHO), it's really annoying to see people make such extensive use of it as it gets butchered for Old Reddit users.
