In a way that is a good thing, forces you to only use the most minimal set of features possible.
It can also backfire horribly.
Asciidoc is the best format I've found so far, but its standardization is also shit.
I was trying the long-form articles on Nostr recently and noticed a few differences between clients. This made me remember something, but I don't remember the source. That Markdown is not exactly standardised.
This also brought org-mode (from Emacs) and orgdown to mind as possible alternatives, and also Gemtext. Gemtext is probably too restricted for that.
Discussion
make a doc spec.
call it nsdoc. for ‘not s*** doc’