--- title: Oryx syntax reference description: Every construct Oryx recognizes, as written and as rendered --- # Oryx syntax reference Every construct Oryx recognizes, markdown and embedded HTML. Each one is shown twice: first its source in a code block, so the reader sees how it is written, then the same lines rendered right under it. On GitHub, the forms outside its own flavor (definition lists, highlight, subscript, superscript, abbreviations, heading IDs) appear as typed in the rendered copy, and Oryx renders them all. Oryx reads CommonMark, the GitHub Flavored Markdown extensions (tables, task lists, strikethrough, footnotes, alerts and math), and the extended syntax listed by the Markdown Guide (heading IDs, definition lists, subscript, superscript, highlight, abbreviations). Emoji shortcodes, smart punctuation and a YAML frontmatter block are recognized too, and the HTML subset GitHub allows in READMEs renders as GitHub renders it. ## Headings ```markdown # Heading 1 ## Heading 2 ### Heading 3 #### Heading 4 ##### Heading 5 ###### Heading 6 Setext Heading 1 ================ Setext Heading 2 ---------------- ``` Levels 1 and 2 are the title and the section headings of this file. The four smaller levels, rendered: ### Heading 3 #### Heading 4 ##### Heading 5 ###### Heading 6 Every heading gets an anchor from its text, in the GitHub style, and joins the sidebar outline. A heading repeated later in the file gets a numbered anchor, `-1` for the second, `-2` for the third, as on GitHub. ### Heading IDs A heading can name its own anchor in braces at the end. The braces stay out of the title. ```markdown ### A heading with its own id {#custom-id} [A link to it](#custom-id) ``` ### A heading with its own id {#custom-id} [A link to it](#custom-id) ## Paragraphs and line breaks A blank line separates paragraphs. A line ending in two spaces or in a backslash breaks inside a paragraph; a plain line ending joins with the next line. ```markdown First paragraph. Second paragraph, with a line ending in two spaces and one in a backslash\ before a plain line ending that joins. ``` First paragraph. Second paragraph, with a line ending in two spaces and one in a backslash\ before a plain line ending that joins. ## Inline styles ```markdown **bold** *italic* ***bold italic*** ~~strikethrough~~ `inline code` Smart punctuation: "quotes", 'quotes', dashes -- and ---, ellipsis... ``` **bold** *italic* ***bold italic*** ~~strikethrough~~ `inline code` Smart punctuation: "quotes", 'quotes', dashes -- and ---, ellipsis... ### Highlight Two equal signs or two colons around a phrase highlight it. The marks must sit at word edges, so `std::vector` in prose stays as typed. ```markdown ==highlighted with equal signs== and ::highlighted with colons:: ``` ==highlighted with equal signs== and ::highlighted with colons:: ### Subscript and superscript A single tilde or caret around a run with no spaces in it lowers or raises the run. A tilde between spaces strikes through instead, as on GitHub. ```markdown H~2~O and CO~2~, E = mc^2^ and x^10^, and ~a struck word~ ``` H~2~O and CO~2~, E = mc^2^ and x^10^, and ~a struck word~ ### Emoji ```markdown Shortcodes: :tada: :rocket: :warning: and pasted emoji ☕ 🚀 ``` Shortcodes: :tada: :rocket: :warning: and pasted emoji ☕ 🚀 ## Lists ```markdown - unordered item * also unordered + also unordered - nested one level - nested two levels 1. ordered item 2. ordered item 1. nested ordered item - [ ] open task - [x] done task ``` - unordered item * also unordered + also unordered - nested one level - nested two levels 1. ordered item 2. ordered item 1. nested ordered item - [ ] open task - [x] done task ### Definition lists A term on its own line, then one or more definitions each starting with a colon. The term renders bold and the definitions indent under it. A definition of several paragraphs indents its later paragraphs by four spaces. ```markdown Oryx : A fast viewer and editor for markdown, code and books. Markdown : A plain text format that reads well as written. : Also the name of the tool that first converted it. ``` Oryx : A fast viewer and editor for markdown, code and books. Markdown : A plain text format that reads well as written. : Also the name of the tool that first converted it. ## Blockquotes and alerts ```markdown > a quote > > > nested one level > [!NOTE] > The five GitHub alert kinds render with their own color and title. > [!TIP] > A tip. > [!IMPORTANT] > Something important. > [!WARNING] > A warning. > [!CAUTION] > A caution. ``` > a quote > > > nested one level > [!NOTE] > The five GitHub alert kinds render with their own color and title. > [!TIP] > A tip. > [!IMPORTANT] > Something important. > [!WARNING] > A warning. > [!CAUTION] > A caution. ## Code ````markdown ```rust fn fenced() -> &'static str { "highlighted when the language is recognized" } ``` ~~~python def tilde_fences(): return "work the same" ~~~ an indented block renders as code too ```` ```rust fn fenced() -> &'static str { "highlighted when the language is recognized" } ``` ~~~python def tilde_fences(): return "work the same" ~~~ an indented block renders as code too Fence languages cover the bundled grammar collection, from `rust` and `python` through `toml`, `kotlin`, `swift`, `typescript`, `dockerfile`, `zig`, `terraform`, `graphql` and `protobuf`. A `diff` fence shows its added lines in green and its removed lines in red. Oryx also opens source files directly and renders the whole file highlighted. ## Tables ```markdown | Left | Center | Right | |:-----|:------:|------:| | a | b | c | | long cells wrap | stripes alternate | columns size to content | ``` | Left | Center | Right | |:-----|:------:|------:| | a | b | c | | long cells wrap | stripes alternate | columns size to content | ## Links and images ```markdown [a link](https://example.com) [a section link](#headings) [a file link](README.md) [a file link to a section](README.md#install) Bare URLs autolink: https://example.com/~user/page Angle brackets too: and [a reference link][ref] [ref]: https://example.com ![local image](examples/oryx-test.png) ![remote image](https://img.shields.io/badge/oryx-syntax-blue.svg) ``` [a link](https://example.com) [a section link](#headings) [a file link](README.md) [a file link to a section](README.md#install) Bare URLs autolink: https://example.com/~user/page Angle brackets too: and [a reference link][ref] [ref]: https://example.com ![local image](examples/oryx-test.png) ![remote image](https://img.shields.io/badge/oryx-syntax-blue.svg) A link to another file opens it in Oryx. Remote images fetch in the background and cache on disk. SVG renders, badges included. A broken path becomes a placeholder with the alt text. A path with a space or a parenthesis in it goes between angle brackets, `![a photo]()`, which is what Oryx writes when you paste or drop a picture into a file. ## Footnotes Footnotes are numbered in order of first use, whatever their labels say, and the definitions gather at the foot of the document in that order. The number at the foot links back to where the footnote is cited. A definition of several paragraphs indents its later paragraphs by four spaces. ```markdown A claim with a footnote,[^note] and another.[^1] [^1]: The definition gathers at the foot of the document. [^note]: This one is used first, so it shows as 1. A second paragraph of the same footnote. ``` A claim with a footnote,[^note] and another.[^1] [^1]: The definition gathers at the foot of the document. [^note]: This one is used first, so it shows as 1. A second paragraph of the same footnote. ## Abbreviations A definition line gives the expansion of an abbreviation. The line disappears, and every whole word matching the label anywhere in the document gets a dotted underline. Hovering the word shows the expansion. ```markdown The specification comes from the W3C, and RTL text reads right to left. *[W3C]: World Wide Web Consortium *[RTL]: right to left ``` The specification comes from the W3C, and RTL text reads right to left. *[W3C]: World Wide Web Consortium *[RTL]: right to left ## Math ````markdown Inline math: $e^{i\pi} + 1 = 0$, or fenced: $`a^2 + b^2 = c^2`$ $$ \sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{\pi^2}{6} $$ ```math \int_{-\infty}^{\infty} e^{-x^2}\,dx = \sqrt{\pi} ``` ```` Inline math: $e^{i\pi} + 1 = 0$, or fenced: $`a^2 + b^2 = c^2`$ $$ \sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{\pi^2}{6} $$ ```math \int_{-\infty}^{\infty} e^{-x^2}\,dx = \sqrt{\pi} ``` All four GitHub notations typeset through the same TeX engine in STIX Two Math. Oryx infers whether a dollar sign is a currency or a math delimiter: a digit right after a closing dollar, as in `$5-$10`, keeps it text. ```latex x_i^2 \quad \frac{a}{b} \quad \binom{n}{k} \quad \sqrt[3]{x^3+y^3} \left( \frac{a}{b} \right)^2 \quad \sum_{n=1}^{\infty} \quad \oint_0^1 \hat{x} \quad \widehat{abc} \quad \vec{v} \quad \overrightarrow{AB} \mathbb{R} \quad \mathbf{v} \quad \mathcal{L} \quad \mathfrak{g} \text{if } \quad \mathrm{d}x \quad \operatorname{Var}(X) \quad \lim_{x \to 0} \alpha \quad \Omega \quad \hbar \quad \forall \quad \nleq \quad \hookrightarrow a\,b \quad c\;d \quad e\!f \quad g \qquad h \begin{pmatrix} a & b \\ c & d \end{pmatrix} \begin{cases} x & x \geq 0 \\ -x & x < 0 \end{cases} \begin{aligned} x &= y \\ z &= w \end{aligned} \newcommand{\avg}[1]{\left\langle #1 \right\rangle} \avg{x^2} ``` A few of these, rendered: $$ \begin{pmatrix} a & b \\ c & d \end{pmatrix} \quad \sqrt[3]{x^3+y^3} \quad \begin{cases} x & x \geq 0 \\ -x & x < 0 \end{cases} \quad \mathbb{R} \quad \hat{x} $$ The command vocabulary follows KaTeX's: Greek letters with their variants, binary operators, relations and their negations, arrows, big operators, delimiters, the seven math alphabets, accents, operator names, spacing, and the environments `matrix`, `pmatrix`, `bmatrix`, `Bmatrix`, `vmatrix`, `Vmatrix`, `smallmatrix`, `cases`, `aligned` and `array`. `\newcommand` and `\renewcommand` define macros with up to nine parameters and one optional default. Anything the engine does not recognize renders as its literal source in place, and runaway macro definitions degrade the same way. ## Frontmatter A YAML block between `---` lines at the very top of a file renders as a metadata panel above the document. This file opens with one. ```markdown --- title: Oryx syntax reference description: Every construct Oryx recognizes, as written and as rendered --- ``` ## Horizontal rules ```markdown --- *** ___ ``` --- *** ___ ## Page breaks A page break ends the page in a PDF export. On screen it shows as a dashed line. Seven spellings work, each alone on its line: the HTML most markdown tools honor, with the CSS 2 names (`page-break-after`, `page-break-before` with `always`) or the CSS 3 names (`break-after`, `break-before` with `page`), and the pandoc habit, three TeX commands. GitHub shows the HTML as nothing and the commands as text. ```markdown
\newpage \pagebreak \clearpage ``` Written in a document, it should look like this: ```markdown The first stretch.
The second stretch. \newpage The third stretch. ``` The rules: - A `

` works in place of the `

`. Capitals, a trailing semicolon and other declarations in the same `style` are fine. - `after` and `before` differ only when the tag holds text: `
Last words
` breaks after the words, `before` breaks before them. An empty tag breaks either way. - A command stands alone in its paragraph, with a blank line above and below. Inside a sentence, a list item or a math block it stays text, so `\newpage` between `$$` fences is TeX, not a break. - Two breaks in a row make one new page. A break at the end of the file adds no empty page. - A book's chapters start on new pages on their own. ## Embedded HTML Oryx renders the HTML subset GitHub allows in READMEs. Anything outside it is stripped, keeping the inner text. ### Structure ```html

An HTML heading, with an anchor like any other

A centered paragraph.

A centered block.

A paragraph on the right.

A left paragraph inside a centered block.

A quote, nestable, stacking with markdown quotes.
  • bullets
    • nested
  1. ordered, honoring start
fn pre_blocks() {}
A term, rendered bold
Its definition, indented.
```

An HTML heading, with an anchor like any other

A centered paragraph.

A centered block.

A paragraph on the right.

A left paragraph inside a centered block.

A quote, nestable, stacking with markdown quotes.
  • bullets
    • nested
  1. ordered, honoring start
fn pre_blocks() {}
A term, rendered bold
Its definition, indented.
### Tables ```html
With theadHeader band
bodyrows
A leading th rowis the header too
ab
A caption renders centered above
no header at allno header band
```
With theadHeader band
bodyrows
A leading th rowis the header too
ab
A caption renders centered above
no header at allno header band
`colspan`, `rowspan` and `align` attributes are ignored; each cell takes one grid slot. An image inside a cell renders like any other. ### Collapsible sections ```html
Closed by default, click to open Markdown works inside. Search still finds this text, and stepping to a match reveals the section.
The open attribute starts it expanded
Sections nest Nested content.
```
Closed by default, click to open Markdown works inside. Search still finds this text, and stepping to a match reveals the section.
The open attribute starts it expanded
Sections nest Nested content.
### Inline ```html bold strong italic emphasis code Ctrl output teletype underline inserted struck deleted struck highlighted small quoted cited defined variable x2 H2O line
break a clickable badge ``` bold strong italic emphasis code Ctrl output teletype underline inserted struck deleted struck highlighted small quoted cited defined variable x2 H2O line
break a clickable badge A `` element reduces to its ``. ### Entities ```html < > & " '   © — é © 😀 ``` < > & " '   © — é © 😀 Entities decode everywhere in HTML text, `
` included: the five basic ones, the Latin-1 set from ` ` to `ÿ` with the accented letters, the common typographic names (`—`, `–`, `…`, `“`, `”`, `•`, `€`, `™`, the arrows), and numeric references in decimal or hex. Anything else stays as typed.

## Useful searches

`Ctrl+F` searches any document, and the `.*` button in the search bar (or `Alt+R`) switches to regular expressions, in the Rust `fancy-regex` flavor. Some searches worth keeping around:

| Pattern | Finds |
|---|---|
| `TODO\|FIXME` | task markers left in a file |
| `\bhttps?://\S+` | web links written out |
| `\d{4}-\d{2}-\d{2}` | dates like 2026-08-16 |
| `\b(\w+) \1\b` | the same word typed twice in a row |
| `"[^"]*"` | anything between double quotes |
| `^#+ ` | heading lines, in a markdown source |
| ` +$` | spaces left at the end of a line |

In the editor, `Ctrl+H` adds a replace field, and a replacement can reuse captured groups:

| Search | Replace | Result |
|---|---|---|
| `(\w+)/(\w+)` | `$2/$1` | swaps the two sides of every pair |
| ` +$` | nothing | strips trailing spaces; `Ctrl+Enter` does the whole file |
| `- \[ \]` | `- [x]` | ticks every open task |