Look like you are correct. I had thought the `::: section` syntax was a recommended approach (if not yet part of the formal spec). In the past, I have used va

Look like you are correct. I had thought the `::: section` syntax was a recommended approach (if not yet part of the formal spec). In the past, I have used various home grown solutions to this, but recently I have been using markdown-it and the accompanying plying markdown-it-container. On the CommonMark forums, I see that the ::: syntax is a leading contender, but that CommonMark itself will not address extensions to basic markdown until after the spec reaches 1.0 https://github.com/markdown-it/markdown-it-container https://github.com/markdown-it/markdown-it-container