I don't really understand what you're looking for, but the comments lead me to think of one thing that might be a little relevant, if not directly useful for yo

I don't really understand what you're looking for, but the comments lead me to think of one thing that might be a little relevant, if not directly useful for you. In mediawiki it's called transclusion. There is a markdown extension with similar functionality called multimarkdown. I looked into it briefly for a project once, but ended up going with basic markdown instead to keep maintenance and content writing as simple as possible. https://en.m.wikipedia.org/wiki/Help:Transclusion https://en.m.wikipedia.org/wiki/Help:Transclusion https://fletcherpenney.net/multimarkdown/ https://fletcherpenney.net/multimarkdown/