The “one more backtick” syntax is a very early Markdown feature explicitly mentioned by John Gruber (originally only for inline code, of course). It might even

The “one more backtick” syntax is a very early Markdown feature explicitly mentioned by John Gruber (originally only for inline code, of course). It might even be in the original “spec”, I don’t remember, but it dates way back and is implemented by virtually all half-decent Markdown parsers. It’s one of the least utilised feature, however, so huge kudos for MyST to clearly explain it and raise awareness.