What content models are allowed?

[tolmasky]

Is there anywhere that defines what children are allowed in what nodes?

[wooorm]

Nope, but I think that there should be!
Why are you pondering this question?

[tolmasky]

I'm doing some post-processing for a program that uses .md for a file format, and I just don't really feel like I have a handle as to whether I'm actually handling all the possible combinations. Do I worry about arbitrary markup in tables? Is this something that isn't necessarily possible the written markdown form but still allowed in the syntax nodes? etc.

[wooorm]

Hmm, interesting. What is and isn’t allowed depends on the node. I think it would make sense to document this. HTML does it as well.
We made a little project mdast-util-phrasing that documents what’s allowed to be in paragraphs (and table cells, for that matter).
I think it’s a good addition, would you like to work on it?