Writing a post

Posts, replies, private messages and signatures are all written in Markdown. This page is the member-facing reference: what the composer's toolbar buttons do, and the syntax behind each of them — including the newer parts, which the toolbar's own Formatting help disclosure only has room to name in passing.

Everything on this page still works with JavaScript off. The toolbar, the live preview, mention suggestions and the "Insert attachment" button are enhancements layered on top of a composer that is a plain <textarea> underneath; typing the syntax by hand always works, whichever came first.

The basics

Bold, italic, strikethrough, links, quotes, lists, headings and code — the everyday Markdown set — work as you would expect, and the composer's own Formatting help disclosure lists the exact syntax for each. This page covers everything past that set.

Syntax-highlighted code

A fenced code block names its language the way GitHub's does:

```ts
const answer = 42
```

The language is highlighted server-side when the post is written — there is no client-side highlighter shipped to the browser, in keeping with the board's no-JS-first rendering. An unrecognised or omitted language falls back to plain, unhighlighted text; it is never an error. The supported languages cover the common ones — TypeScript/JavaScript, Python, Go, Rust, Java, C/C++/C#, Ruby, PHP, Kotlin, Swift, SQL, HTML, CSS, Markdown, YAML, JSON, TOML, INI, bash, Dockerfile, GraphQL, diff and HTTP — under common aliases (js, py, sh, yml, and so on).

Spoilers

:::spoiler
The ending is a twist nobody expected.
:::

Renders as a native, no-JavaScript-required disclosure — closed by default, opened with a click or a keypress. spoiler is reserved: it always works, on every board, whatever directives an administrator has or has not configured. The composer's Spoiler toolbar button wraps your selection in the fences for you.

Mentioning a member

Typing @ followed by a few letters of a username opens a short list of suggestions — pick one, or keep typing and press Enter. This is an enhancement only: the underlying syntax is still @username, so typing it out by hand, with JavaScript off or on, works exactly the same and still notifies the member. Suggestions never include a member on your ignore list, and only appear for people whose profile you are allowed to see.

Link previews

A link to YouTube or Vimeo, alone on its own line, unfurls into a small card — a thumbnail, the title, and who posted it — once the post is saved:

https://www.youtube.com/watch?v=dQw4w9WgXcQ

A link that shares a paragraph with other text is left as a plain link; only a link on a line by itself is treated as something worth a preview of its own. This only happens on boards that have opted into loading remote images at all (the same setting that governs whether an ![image alt text](https://example.com/pic.png) from off-board loads) — an administrator who has kept the board's content-security policy locked to same-origin images gets no cards, and no request to YouTube or Vimeo is ever made on their behalf. The card itself is a static image and text — never an embedded player — so it costs nothing beyond that same image allowance.

Placing an attachment inline

By default, every file you attach to a post is shown in a list below it. To place one inline — where it belongs in what you wrote, the way an image does — click the toolbar's Insert attachment button (the paperclip). It uploads the file immediately, before the post itself is submitted, and drops [attachment=id] at your cursor once it is done; the file still also appears in the attachment list once the post is saved. An id you did not upload yourself never resolves to anything in somebody else's post — typing one by hand does not work.

Everything else stays server-rendered

None of the above needed a client-side markup renderer, a syntax- highlighting library shipped to the browser, or a script tag on the rendered post itself. What changes with JavaScript off is only the composing experience — the toolbar, the mention list, the "Insert attachment" button, the live preview tab — never what a saved post looks like once someone reads it.