Everything MDRS can do, in one post

Welcome to fkp.my.id. This post is written in MDRS 1.0, the Markdown dialect that powers every article here. It is plain Markdown first. Everything after that is an extension, and each one appears at least once below, so the source of this post doubles as a reference.

Writing text

A paragraph is just lines of text. A single line break inside it becomes a space, and a backslash at the end of a line
forces a hard break.

You get bold, italic, both, strikethrough and inline code. Inline HTML covers the rest: press Ctrl + K, write H₂O and E = mc², highlight a phrase, underline one, or expand an MDRS abbreviation. Small print is fine too, as are short quotations, titles of works and dates like 17 October 2026.

Escape any punctuation with a backslash: *not italic*, # not a heading, and $$ not math. Entities work as well: © — →.

Links and images

Links can be inline, by reference, or bare: https://github.github.com/gfm/ and www.example.com both become links, as does an address like hello@example.com. Links to other sites open in a new tab and get a small arrow; links within this site don't.

Definitions

MDRS

Markdown Rich Syntax, a drop-in superset of CommonMark and GFM.

.mdrs

The file extension for documents that use it.

Lists

Bullets and numbers work as you'd expect, and lists nest:

• Server

  • KaTeX math
  • Variables and live data
• Browser

  • Mermaid diagrams
  • Charts

3. Numbered lists can start anywhere,
4. and the numbers after the first one don't matter.
5. This is still item five.

A loose list, with blank lines between items, keeps its paragraphs apart:

• The first item has room to breathe.

• So does the second one.

Task states

GFM gives you [ ] and [x]. MDRS adds five more states:

• Done:
  Write the engine
• In progress:
  Write the docs
• Failed:
  Port the parser to Rust
• Skipped:
  Support single-dollar math
• Important:
  Keep it a drop-in superset
• Question:
  Ship a VS Code extension?
• To do:
  Publish the first release

  • Done:
    Reserve the package names
  • To do:
    Write the changelog

They work in numbered lists too:

1. Done:
   Reserve @mdrs/core
2. In progress:
   Extract the engine
3. To do:
   Tag v0.1.0

Quotes and tables

A blockquote is a > at the start of a line.

Quotes nest, and hold any Markdown:

• even lists

Code

Fences take a language, an optional filename and an optional mark to highlight lines:

export function greet(name: string) {
    const message = `Hello, ${name}!`;
    console.log(message);
    return message.length;
}

Diffs are coloured line by line:

- const engine = 'markdown';
+ const engine = 'mdrs';

A shell fence without script constructs becomes a command block, with a prompt instead of line numbers:

bun add @mdrs/core

Indented code works too:

plain indented code
keeps its spacing

Callouts and alerts

GitHub's alert syntax renders the same callouts, so READMEs look right here:

Custom callouts take a title and an optional Lucide or Bootstrap icon:

Details

Tabs and snippets

Snippet groups add copy and download controls. Groups with the same key stay in sync, so picking "npm" below switches both:

bun add @mdrs/core

npm install @mdrs/core

bun run dev

npm run dev

Steps

Media

A link ending in .mp4 or .webm, written as an image (![Clip](https://…/clip.mp4)), becomes a <video> player.

Math

Inline formulas sit in the text, like Euler's identity $e^{i\pi} + 1 = 0$ or $x^2$. Prices stay prices, though: a single $ never starts math, so a coffee is $5 and a book is $10.

Formulas can use variables. There are 5 headline features:

$n = 5, \quad \binom{n}{2} = 10$

Diagrams and charts

Variables and live data

This post's :::define block mixes literals, expressions and live data. Farhan Kurnia Pratama has published 1 posts on fkp.my.id so far, and this one was written in 2026.

• The second headline feature is tabs.
• The engine's file extension is ${engine.extension}, and it ships 14 directives.
• Is this build stable? true.

Conditional text only shows when its condition is true, and can hold its own expressions:

This is a stable build of MDRS 1.0.

The newest post is Everything MDRS can do, in one post.

A backslash keeps the syntax literal: ${site} and [text].${stable} stay as written.

Footnotes and references

MDRS renders math on the server^[1] and diagrams in the browser^[2]. Cite a source twice^[3] and it gets a back-link for each use^[3].

Showing MDRS source

Code spans and code blocks never render MDRS: :::note, ${site} and $$x$$ stay literal. For whole examples, :::ignore-render prints the source as-is, and a longer fence can hold a complete directive:

:::tip
Directives open with `:::name` and close with `:::`.
:::

That's the whole language, in one post. Every rule behind it is plain enough to fit in your head: write Markdown, and reach for a directive only when Markdown runs out.