@campfireman I came across this advocacy document today when perusing the venerable SQLite documentation. What they call application file formats, I think, applies to Cooklang, too? If yes, Cooklang possibly falls under their first category of application file formats, fully custom formats. I find it interesting that they say that those are usually binary. I suspect that their document predates current Markdown use cases, and does not take modern hardware into account.
https://sqlite.org/appfileformat.html