[breuleux]

If you want another data point, I made my own markup language a while back that aims for markdown-like simplicity while making it easy to define simple macros and operators: http://breuleux.github.io/quaint/

It's pretty extensive. I still use it for my own writing, although I'm probably the only one.

[svnt]

Do you have an example of a document where it’s special features are more heavily used? Most of the posts I saw were basically just paragraphs and italicized sections.

[breuleux]

I don't have a whole lot that are public. This section describes one of advanced features I use most: http://breuleux.github.io/quaint/syntax.html#rules

I've used it to create operators for stuff like:

* Lead caps

* Formatting dialogue in a screenplay

* Marking something that's a prop in a screenplay

* Parametric links (e.g. defining @john so that it creates a link to the john handle on X/Twitter)

* Tooltips