Markdown Cheat Sheet

By the Syncfusion DevTutorials team · Last updated

Every syntax rule, GFM extra, platform extension, frontmatter rule, AI-native file and check from the course on one page, with live boxes.

What you will learn

  • Find any Markdown rule or AI-native file format from the course quickly

Markdown Cheat Sheet

Everything from the course on one page. Each box is live: change it, and switch between CommonMark, GitHub (GFM) and Docs site to see where each feature works.

Core Syntax

These work in every flavour.

You wantYou writeNotes
Heading# Title … ###### Smalla space after the # signs
Paragraphtext, then a blank lineone line break alone does not start a new line
Line breakend the line with \two trailing spaces also work, but are invisible
Bold**bold**no spaces just inside the stars
Italic*italic*underscores inside words are safe
Bullet list- itemone mark per file; 2 spaces to nest
Numbered list1. steponly the first number counts; 3 spaces to nest
Link[text](path)nothing between ] and (
Heading link[text](#refund-window)anchors are added by the renderer
Reference link[text][label] and [label]: urlthe label must match
Web address<https://example.com>a bare address is a link only in GFM
Image![alt text](path)always write alt text
Inline code`npm test`marks do nothing inside code
Code blockthree backticks, a language, the code, three backticksalways close it
Quote> text>> for a quote in a quote
Divider--- with a blank line abovewithout the blank line it makes a heading
Escape\*, \#, \_, \[shows the mark as text

The core in one box

# Refund policy

Refunds are allowed within **30 days** of delivery.\
After that, offer a *voucher*.

1. Open the order
2. Check the receipt
   - Card or bank transfer

See the [shipping guide](docs/shipping.md) and <https://commonmark.org>.

![Refund flow: request, check, approve](/markdown-assets/refund-flow.svg)

```bash
npm test
```

> Ask a lead if you are not sure.

---

2023\. A year, not a list.

GFM Extras

You wantYou writeWithout GFM
Tableheader row, |---|---|, rowsa paragraph of pipes
Right-aligned column---: in the divider—
Pipe in a cell|the cell splits
Task list- [ ] open and - [x] done[ ] shown as text
Strikethrough~~old~~tildes shown as text
Footnotetext[^1] and [^1]: noteshown as text
Automatic linkshttps://example.complain text

The GFM extras

| Plan | Price |
|---|---:|
| Basic | Free |
| Pro | ₹999 |

- [x] Fix refund rounding
- [ ] Add order search

~~3 days~~ 2 days.[^1]

[^1]: For card refunds.

Platform Extensions

You wantYou writeWorks on
Note or warning box> [!NOTE], > [!WARNING] (also TIP, IMPORTANT, CAUTION)GitHub, many docs sites
Diagrama code block with the hint mermaidGitHub, most docs sites
Data about the fileYAML between two --- lines at the very topdocs sites, AI tools
Collapsible section<details>, <summary>, then a blank lineGitHub and most HTML-friendly renderers
Keyboard key<kbd>Ctrl</kbd>where HTML is allowed
Maths$a^2$ inline, $$ … $$ on its own linesGitHub and many docs sites; elsewhere write \$ for a dollar sign

Platform extensions

---
title: Refund policy
owner: support-team
---

> [!WARNING]
> Refunds over ₹5,000 need a manager's approval.

```mermaid
flowchart LR
  A[Request] --> B[Check] --> C[Approve]
```

<details>
<summary>Show the refund times</summary>

- Card: up to 3 working days
- Bank transfer: up to 5 working days

</details>

Frontmatter and YAML

RuleExample
First line is exactly ---nothing above it, not even a blank line
key: value, with a space after the colontitle: Refund policy
Quote values with : or # or a leading special charactertitle: "Refunds: the rules", channel: "#refunds"
Quote numbers that must stay textversion: "1.10", zip: "012"
Liststags: [refunds, billing] or lines starting -
Groupsa key, then indented keys below it, with spaces
Long text`keeps line breaks,>` folds them
Nevertabs in the indent

AI-Native Files

FileWhereLoadsMust have
AGENTS.mdrepo root; subfolders for local rulesevery sessioncommands; only what the code cannot say; well under 150 lines
CLAUDE.mdrepo rootevery Claude Code session@AGENTS.md to share one file
Cursor rule.cursor/rules/*.mdcwhen its globs match, or alwaysdescription, globs, alwaysApply
Skill.claude/skills/<name>/SKILL.md (Codex: .agents/skills/, Cursor: .cursor/skills/)name and description at start; body when pickedname matching the folder; a description with what, when and when not
Subagent.claude/agents/<name>.mdwhen work is handed to itname, description; a body with scope, checks and output format
Specspecs/<feature>.mdwhen you point the agent at itgoal, non-goals, checkable acceptance criteria, no TBD
Codex subagent.codex/agents/<name>.tomlwhen work is handed to itname, description, developer_instructions
llms.txtdocs site rootwhen an AI tool fetches your docs# title, > summary, ## lists of - [name](url): notes

The paths for the tool you picked:

SKILL.md skeleton

---
name: refund-check
description: "Checks a refund request against the refund policy. Use when a refund is requested or late. Do not use for shipping or tracking."
---

# Refund check

## Steps

1. Find the order.
2. Check the 30-day window.

## Output

One line: approve, voucher or needs approval, then the reason.

The Course's Checks

IdChecksFrom
MD001–MD059headings, blank lines, code hints, alt text, bare links, link textmarkdownlint rule ids
AGT001–AGT004AGENTS.md size, commands, filler, hidden commentsthis course
SKL001–SKL005SKILL.md frontmatter, name, folder, description, lengththis course, from the Agent Skills spec
SUB001–SUB003subagent frontmatter, name, bodythis course, from Claude Code's docs
SPC001–SPC007spec goal, criteria, non-goals, vague words, open questions, conflicting numbers, unclear criteriathis course
LNK001link to a file that does not existthis course
LLM001–LLM005llms.txt title, summary, headings, file-list items, notesthis course, from llmstxt.org
STY001–STY004bold overuse, header inflation, deep bullets, emoji headingsthis course

Pages in This Course