Headings

Six levels, one to six hashes. The space after the hashes is required — `#Heading` renders as literal text, not a heading.

# Release notes
## Version 2.1
### Bug fixes
#### Storage layer

Skipping levels (H1 straight to H3) renders fine but reads poorly to screen readers and search engines. Go in order where you can.

Bold, italic and strikethrough

One marker for italic, two for bold, three for both. Tildes give you strikethrough.

*italic* and _also italic_

**bold** and __also bold__

***bold italic***

~~struck through~~

Underscores do not work mid-word — `snake_case_name` stays intact, which is exactly what you want when writing about code. Asterisks do split words.

Lists

Dashes, asterisks or plus signs for bullets; numbers for ordered lists. Indent by two spaces to nest.

- Parser
- Renderer
  - Syntax highlighting
  - Math
- Storage

1. Compress
2. Encrypt
3. Store

Ordered lists renumber themselves. Writing 1. three times still renders 1, 2, 3 — handy when reordering steps.

Task lists

A GitHub Flavored Markdown extension. Square brackets with a space are unchecked, with an x are checked.

- [x] Write the parser
- [x] Add syntax highlighting
- [ ] Ship expiry options
- [ ] View counter

Links

Inline links put the URL right after the text. Reference links move it to the bottom, which keeps long paragraphs readable.

[Inline link](https://mdbin.sivaramp.com)

[Reference link][docs]

Bare URLs autolink too: https://mdbin.sivaramp.com

[docs]: https://mdbin.sivaramp.com "Optional title"

Images

Same as a link with a leading exclamation mark. The bracketed text is alt text, not a caption — it is what shows if the image fails to load.

You writeCopy

![A markdown logo](https://mdbin.sivaramp.com/mdbin.png)

[![Clickable image](https://mdbin.sivaramp.com/mdbin.png)](https://mdbin.sivaramp.com)

You get

Wrapping an image in a link is how you make it clickable — that nested form is why link and image syntax look so similar.

Code and syntax highlighting

Backticks for inline code, three backticks for a block. Name the language after the opening fence to get highlighting.

Call `decrypt()` before rendering.

```typescript
export async function decrypt(blob: string, password: string) {
  const key = await deriveKey(password, salt)
  return crypto.subtle.decrypt({ name: 'AES-GCM', iv }, key, data)
}
```

export async function decrypt(blob: string, password: string) {  const key = await deriveKey(password, salt)  return crypto.subtle.decrypt({ name: 'AES-GCM', iv }, key, data)}

To show literal backticks inside inline code, wrap with more backticks than you need to display.

Tables

Pipes separate columns, and the second row sets alignment. Colons control it: left, right, or both for centred.

| Algorithm | Key size | Authenticated |
|:----------|---------:|:-------------:|
| AES-GCM   |      256 | Yes           |
| AES-CBC   |      256 | No            |
| ChaCha20  |      256 | Yes           |

The dashes do not need to line up. Ugly source renders into a clean table, so do not waste time aligning by hand.

Blockquotes

A leading angle bracket. Stack them to nest, and keep using markdown inside.

> Encryption happens in the browser.
>
> > The server only ever sees ciphertext.

Math

LaTeX via KaTeX. Single dollar signs for inline math, double for a centred block.

Key derivation runs $n = 310{,}000$ iterations.

$$
\text{DK} = \text{PBKDF2}(\text{PRF}, P, S, c, \text{dkLen})
$$

Not part of standard markdown — most renderers show this as literal text. It works here, on GitHub, and in most documentation tooling.

Mermaid diagrams

A fenced code block tagged `mermaid` becomes a rendered diagram. Flowcharts, sequence diagrams, state machines and more.

```mermaid
flowchart LR
  A[Write markdown] --> B{Encrypt?}
  B -- Yes --> C[Derive key in browser]
  B -- No --> D[Compress]
  C --> E[Store ciphertext]
  D --> E
```

Also outside standard markdown. Diagrams live as text, so they stay diffable in version control.

Horizontal rules

Three or more dashes, asterisks or underscores on their own line.

Above the line

---

Below the line

Put a blank line before the dashes. Directly under a line of text, they turn that text into a heading instead.

Line breaks and paragraphs

A blank line starts a new paragraph. A single newline is usually collapsed — end a line with two spaces to force a break inside one paragraph.

This line ends with two spaces
so this sits directly underneath it.

This is a separate paragraph.

Trailing whitespace being meaningful is markdown at its worst. Most editors strip it on save, so prefer a blank line where you can.

Footnotes

Reference a note inline, define it anywhere. Rendered output collects them at the bottom with a link back.

Content is compressed before storage.[^brotli]

[^brotli]: Brotli, which typically beats gzip on text.

Inline HTML

Markdown passes most HTML straight through, which covers whatever the syntax cannot express.

<details>
<summary>Click to expand</summary>

Hidden until opened. Markdown still works **in here**.

</details>

Keep a blank line between an HTML tag and markdown inside it, or the markdown will not be parsed. Anywhere rendering untrusted input, HTML should be sanitised.

Escaping

Put a backslash before a character to render it literally instead of as syntax.

\*not italic\*

\# not a heading

A literal backslash: \\