Toggle

Tier

rich

Surfaces

page

Fallback

native

State

settled

A fold: the one HTML element this format uses, because GitHub and Obsidian collapse it natively.

<details>
<summary>More</summary>

Hidden body.

</details>

The blank lines are required — one after </summary> and one before </details>. Without them the whole thing parses as a single raw HTML node and the Markdown inside it never parses at all.

The summary is the toggle's own words. The body is the blocks that follow it, carried one indent level in, so a toggle holds anything a page holds.

Fallback: GitHub and Obsidian draw a working fold. Elsewhere the tags show and the body is read as ordinary Markdown below them — nothing a person wrote is hidden.