All of these are supported in pandoc markdown:

> .mdv is strict CommonMark plus four additions:

> YAML front-matter for title, theme, named styles, and dataset references.

> Fenced blocks for data/visuals: ```chart type=bar x=region y=sales.

> ::: containers for styled regions and layout: ::: callout / ::: columns.

> ::: toc for an auto-generated table of contents.