Transclusion is something that Ted Nelson talked about from the beginning and is important in text markup whether for xanadu, html, markdown or xml etc. There are several implementations in markdown that do transclusion, it would be interesting in this sense to have a common and unique markup for this. In such a connected, dynamic and unique world I believe this: transclusion in commonmark. In my opinion this feature would make my life easier - it would be something I could use more often, it would be a replacement for Obsidian, Notion, org-mode.