[bityard]

`---` is already used in Markdown for horizontal rules?

[_ache_]

Yeap, along with `+++`, `**` and mixing if I remember correctly. I don't understand the logic of using an non-standard syntax because some non-standard implementations may not render correctly.

Actually, yes, now you know for a fact that none of the Markdown implementation will render it correctly.

So, I guess, they used `~~~` instead and it was an error in OP post.

[nicoburns]

The problem here is that if you use ``` as a token in a non-markdown language, then it's going to be very hard to embed that code in a markdown code block. That problem doesn't happen with other syntax as it's already escaped by the code block. `---` inside a markdown code block will render as a literal `---`.

[yencabulator]

To embed content with multiple sequential backticks, use more backticks than the max run.

[nicoburns]

In theory, yes. But not all markdown implementations support this properly.

[yencabulator]

The CommonMark spec even has an example test case! The excuses for poor implementations are pretty thin.

[lilyball]

Not all markdown implementations are CommonMark

[yencabulator]

There's not much reason to be anything else than CommonMark + extensions.