Topic on Talk:Release notes

I think mw-json HTML tables are a useful feature, but there seems to be no mention of it in the changelog.

Does anyone know when it was introduced so we can add it? And did the JSON content model exist before mw-json HTML tables were introduced?

Proper JSON support was brought into core in d2a82fcb604 which first shipped in MediaWiki 1.24.0 (it earlier sat in an extension). The JSON content model constant CONTENT_MODEL_JSON was created as part of that patch.