Markdown Cheatsheet

A comprehensive reference for every Markdown flavor

This guide covers markdown syntax from basic to advanced, across all major flavors. Whether you're writing documentation, blog posts, or technical notes, this reference has you covered.

Flavor	Best For
CommonMark	Universal compatibility
GFM	GitHub repos, issues, wikis
Pandoc	Academic papers, books
Kramdown	Jekyll/Ruby sites
MDX	React documentation
Obsidian	Personal knowledge bases

## 1. Basic Syntax (Original Markdown)

### Headings

```markdown
# Heading 1
## Heading 2
### Heading 3
#### Heading 4
##### Heading 5
###### Heading 6

Alternative H1
==============

Alternative H2
--------------
```

### Emphasis

```markdown
*italic* or _italic_
**bold** or __bold__
***bold italic*** or ___bold italic___
~~strikethrough~~ (GFM extension)
```

### Lists

**Unordered:**

```markdown
* Item 1
* Item 2
  * Nested item 2.1
  * Nested item 2.2
    * Deep nested
- Item with dash
+ Item with plus
```

**Ordered:**

```markdown
1. First item
2. Second item
   1. Nested ordered
   2. Another nested
3. Third item
1. Numbers don't need to be sequential
```

### Links & Images

```markdown
[Inline link](https://example.com "Optional Title")
[Reference link][ref1]
[Implicit reference][]
<https://automatic-link.com>
<email@example.com>

![Alt text](image.jpg "Optional title")
![Reference image][img-ref]

[ref1]: https://example.com "Reference Title"
[Implicit reference]: https://example.com
[img-ref]: image.jpg "Image Reference"
```

### Blockquotes

```markdown
> Single line quote

> Multi-line quote continues here
> and here

> Nested quotes
>> Can be nested
>>> Multiple levels deep
```

### Code

```markdown
Inline `code` with backticks

    Code block with 4 spaces
    or tab indentation
```

~~~markdown
```
Fenced code block
Multiple lines
```

```javascript
// Syntax highlighted (GFM)
function hello() {
    console.log("Hello, World!");
}
```
~~~

### Horizontal Rules

```markdown
Three or more:

---
Hyphens

***
Asterisks

___
Underscores
```

---

## 2. GitHub Flavored Markdown (GFM)

### Tables

```markdown
| Left-aligned | Center-aligned | Right-aligned |
| :----------- | :------------: | ------------: |
| Cell 1       | Cell 2         | Cell 3        |
| Longer text  | **Bold**       | *Italic*      |

Minimal table:

First Header | Second Header
------------ | -------------
Content Cell | Content Cell
```

**Rendered:**

| Left-aligned | Center-aligned | Right-aligned |
| :----------- | :------------: | ------------: |
| Cell 1       | Cell 2         | Cell 3        |
| Longer text  | **Bold**       | *Italic*      |

### Task Lists

```markdown
- [x] Completed task
- [ ] Uncompleted task
- [ ] Another todo
  - [x] Nested completed
  - [ ] Nested uncompleted
```

**Rendered:**

- [x] Completed task
- [ ] Uncompleted task
- [ ] Another todo
  - [x] Nested completed
  - [ ] Nested uncompleted

### Username & Issue Mentions

```markdown
@username (GitHub only)
#123 (Issue reference)
user/repo#123 (Cross-repo issue)
```

### Emoji

```markdown
:smile: :heart: :thumbsup: :100:
:rocket: :octocat: :+1: :-1:
```

### Syntax Highlighting with Language

~~~markdown
```python
def factorial(n):
    """Calculate factorial"""
    if n <= 1:
        return 1
    return n * factorial(n - 1)
```

```diff
- Removed line
+ Added line
! Important change
# Comment
```
~~~

**Rendered:**

```python
def factorial(n):
    """Calculate factorial"""
    if n <= 1:
        return 1
    return n * factorial(n - 1)
```

```diff
- Removed line
+ Added line
! Important change
# Comment
```

### SHA References

```markdown
16c999e8c71134401a78d4d46435517b2271d6ac
mojombo@16c999e8c71134401a78d4d46435517b2271d6ac
mojombo/github-flavored-markdown@16c999e
```

---

## 3. CommonMark Extensions

### Autolinks

```markdown
www.example.com (some parsers)
https://example.com
ftp://files.example.com
```

### Disallowed Raw HTML (optional)

```html
<script>alert('This may be stripped');</script>
<div class="custom">Safe HTML allowed in some flavors</div>
```

### Entity & Numeric Character References

```markdown
&nbsp; &amp; &lt; &gt; &quot; &apos;
&#65; &#x41; &#8230;
```

---

## 4. MultiMarkdown Extensions

### Metadata Block

```markdown
Title: Document Title
Author: John Doe
Date: 2024-01-01
Tags: markdown, reference
Base Header Level: 2
```

### Footnotes

```markdown
Here's a sentence with a footnote[^1].

Here's another with a longer note[^longnote].

Inline footnote^[This is an inline footnote].

[^1]: This is the footnote.

[^longnote]: Here's one with multiple paragraphs.

    Indent paragraphs to include them in the footnote.

    > Even blockquotes in footnotes!
```

### Citations

```markdown
This is a statement that needs citation[p. 23][#Doe:2024].

Multiple citations[p. 10][#Smith:2023; p. 24][#Doe:2024].

[#Doe:2024]: John Doe. *Sample Book*. 2024.
[#Smith:2023]: Jane Smith. *Another Book*. 2023.
```

### Math (also Pandoc)

```markdown
Inline math: $E = mc^2$ or \\(a^2 + b^2 = c^2\\)

Display math:
$$
\sum_{i=1}^{n} x_i = \int_{0}^{1} f(x) dx
$$

\\[
\frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
\\]
```

### Abbreviations

```markdown
HTML is great.
CSS is awesome.

*[HTML]: HyperText Markup Language
*[CSS]: Cascading Style Sheets
```

### Definition Lists

```markdown
Term 1
:   Definition 1
:   Another definition

Term 2
:   Definition with *inline* **formatting**

Compact Definition
: Brief description
```

### Smart Typography

```markdown
"Smart quotes" and 'single quotes'
En-dash -- and em-dash ---
Ellipsis...
```

### Cross-references

```markdown
See [](#heading-1) for more info.
As discussed in [](#fig:example).

![Example Figure][fig:example]

[fig:example]: image.jpg "Example" width=500px height=300px
```

---

## 5. Pandoc Markdown Extensions

### Div Blocks

```markdown
::: {.note #special-note}
This is a special note block with class and id.
:::

::: warning
This is a warning block.
:::

::: {.sidebar}
Sidebar content here
:::
```

### Span Elements

```markdown
This is [special text]{.highlight #text-id} inline.

[Small caps]{.smallcaps} text.
```

### Line Blocks

```markdown
| The limerick packs laughs anatomical
| In space that is quite economical.
|    But the good ones I've seen
|    So seldom are clean
| And the clean ones so seldom are comical
```

### Fancy Lists

```markdown
(1) First item
(2) Second item
    a. Sub-item
    b. Another sub
        i. Deep nesting

#. Auto-numbered
#. Continues numbering

i. Roman numerals
ii. Continue
    A. Upper letters
    B. More items

Example lists:
(@) First example
(@) Second example

Later reference to example (@).
```

### Grid Tables

```markdown
+---------------+---------------+--------------------+
| Fruit         | Price         | Advantages         |
+===============+===============+====================+
| Bananas       | $1.34         | - built-in wrapper |
|               |               | - bright color     |
+---------------+---------------+--------------------+
| Oranges       | $2.10         | - cures scurvy     |
|               |               | - tasty            |
+---------------+---------------+--------------------+
```

### Pipe Tables (simpler)

```markdown
| Right | Left | Default | Center |
|------:|:-----|---------|:------:|
|   12  |  12  |    12   |   12   |
|  123  |  123 |   123   |  123   |
|    1  |    1 |     1   |    1   |
```

### Superscript and Subscript

```markdown
H~2~O is water.
X^2^ is X squared.
^superscript^ and ~subscript~
```

### Inline Code Attributes

```markdown
`code`{.python}
`var x = 5;`{#mycode .javascript .numberLines startFrom="100"}
```

### Raw Blocks

~~~markdown
```{=html}
<div class="custom-html">
  Raw HTML preserved exactly
</div>
```

```{=latex}
\begin{align}
  E &= mc^2
\end{align}
```

```{=mediawiki}
{{Template|arg=value}}
```
~~~

### YAML Metadata Block

```yaml
---
title: Complete Reference
subtitle: Every Markdown Feature
author:
  - name: John Doe
    affiliation: University
  - name: Jane Smith
date: 2024-01-01
abstract: |
  This is a multi-line
  abstract in YAML.
tags: [markdown, documentation]
keywords:
  - markdown
  - reference
lang: en-US
toc: true
toc-depth: 3
numbersections: true
---
```

### Native Spans and Divs

```html
<div custom="attribute">
Native div with attributes
</div>

<span class="custom">Native span</span>
```

---

## 6. Extended Features (Various Flavors)

### Admonitions/Callouts

```markdown
!!! note "Optional Title"
    This is a note admonition.

!!! warning
    This is a warning without title.

!!! danger "Critical"
    Important danger message.

!!! tip
    Helpful tip here.

!!! important
    Important information.

!!! example "Code Example"
    ```python
    print("Hello")
    ```
```

**GitHub-style callouts:**

```markdown
> [!NOTE]
> GitHub-style callout

> [!WARNING]
> Another style of callout

> [!TIP]
> Helpful information

> [!IMPORTANT]
> Crucial information

> [!CAUTION]
> Be careful here
```

### Keyboard Keys

```html
Press <kbd>Ctrl</kbd> + <kbd>C</kbd> to copy.
<kbd>⌘</kbd> + <kbd>V</kbd> on Mac.

++ctrl+alt+del++ (some flavors)
```

**Rendered:**

Press <kbd>Ctrl</kbd> + <kbd>C</kbd> to copy.
<kbd>⌘</kbd> + <kbd>V</kbd> on Mac.

### Mark/Highlight

```markdown
==Highlighted text== (some flavors)
<mark>HTML mark element</mark>
{==highlighted==} (critic markup)
```

**Rendered:**

<mark>HTML mark element</mark>

### Insert/Delete (Critic Markup)

```markdown
{++inserted text++}
{--deleted text--}
{~~old~>new~~}
{>>comment<<}
{==highlight==}{>>with comment<<}
```

### Details/Summary

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

Hidden content here with:
- Lists
- **Formatting**
- Etc.

</details>

<details open>
<summary>Expanded by default</summary>
This is visible initially.
</details>
```

**Rendered:**

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

Hidden content here with:
- Lists
- **Formatting**
- Etc.

</details>

### Table of Contents

```markdown
[[TOC]] (some flavors)
[TOC] (other flavors)
{:toc} (kramdown)
```

### Include Files

```markdown
<<[file.md]
<<(file.md)
{{file.md}}
!include file.md
{! file.md !}
```

### Diagrams

~~~markdown
```mermaid
graph LR
    A[Start] --> B{Decision}
    B -->|Yes| C[Do this]
    B -->|No| D[Do that]
    C --> E[End]
    D --> E
```

```plantuml
@startuml
Alice -> Bob: Hello
Bob --> Alice: Hi!
@enduml
```

```graphviz
digraph G {
    A -> B;
    B -> C;
    C -> A;
}
```
~~~

### Custom Containers

```markdown
::: {.theorem #pythagorean}
**Pythagorean Theorem**: $a^2 + b^2 = c^2$
:::

::: note
Custom note container
:::

::: {.callout-note}
## Note Title
Note content
:::
```

### Attributes on Elements

```markdown
![](image.jpg){width=50% height=30px}

[Link](url.com){.external target="_blank"}

Paragraph with attributes.
{: .custom-class #custom-id}
```

### Hard Line Breaks

```markdown
Line ending with two spaces
creates a hard break.

Line ending with backslash\
also creates a hard break (some flavors).
```

### Video Embeds (Some Flavors)

```markdown
![](video.mp4)
![](https://youtube.com/watch?v=id)

@[youtube](dQw4w9WgXcQ)
```

### Special Lists

```markdown
Term
  ~ Definition using tilde

Tight list:
* item1
* item2

Loose list:

* item1

* item2
```

---

## 7. Edge Cases & Special Characters

### Escaping

```markdown
\*Not italic\*
\`Not code\`
\[Not a link\](not a url)
\# Not a heading
\| Not a table
\1. Not a list
```

### Special Characters

```markdown
&copy; &trade; &reg; &deg; &plusmn; &ne; &le; &ge;
&rarr; &larr; &uarr; &darr; &harr;
&frac12; &frac34; &infin; &sum; &prod;
```

**Rendered:**

&copy; &trade; &reg; &deg; &plusmn; &ne; &le; &ge;
&rarr; &larr; &uarr; &darr; &harr;
&frac12; &frac34; &infin; &sum; &prod;

### Zero-Width Characters

```markdown
Zero&#8203;Width&#8203;Space
Word&shy;Break&shy;Hint
```

### Nested Structures

```markdown
> Blockquote with:
> - List item 1
> - List item 2
>   ```python
>   # code in list in quote
>   print("nested")
>   ```
>   > Nested quote in list
>
> 1. Ordered in quote
> 2. More ordered
>
> | Table | In | Quote |
> |-------|----|----|
> | Works | In | Some |
```

### Complex Nesting

```markdown
1. List with paragraph

   Multiple paragraph in list item.

   > Quote in list

   ```
   code in list
   ```

2. Another item
   - [ ] Task in ordered list
   - [x] Completed
```

### Unicode & Emoji

```markdown
📝 ✨ 🚀 💻 🎯 ⚡ 🔥 ✅ ❌ ⚠️
α β γ δ ε ζ η θ
© ® ™ • · × ÷ ±
```

### Comments

```markdown
<!-- HTML comment -->
[//]: # (This is also a comment)
[//]: <> (Another comment style)
[comment]: <> (Yet another)
```

---

## 8. Kramdown Specific

### Block Attributes

```markdown
{: .class #id key="value"}
This paragraph has attributes.

> Block quote with attributes.
{: .pullquote}
```

### Options

```markdown
{::options parse_block_html="true" /}
{::options auto_ids="false" /}
```

### No Markdown

```markdown
{::nomarkdown}
This *won't* be **parsed**.
{:/}
```

### Comments

```markdown
{::comment}
This is a kramdown comment.
{:/comment}
```

---

## 9. Markdown Extra

### Special Attributes

```markdown
Header {#header-id .header-class}
================================

[link](url){#link-id .link-class}
```

### Fenced Code Attributes

~~~markdown
~~~ {.python #mycode .numberLines startFrom="10"}
def hello():
    print("Hi")
~~~
~~~

### Markdown Inside HTML

```html
<div markdown="1">
This is *markdown* inside **HTML**.
</div>

<div markdown="block">
- List inside HTML
- Another item
</div>
```

### Backslash Escapes

```markdown
\\ \` \* \_ \{ \} \[ \] \( \) \# \+ \- \. \!
```

---

## 10. R Markdown / Quarto

### Code Chunks

~~~markdown
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

```{python}
#| label: fig-plot
#| fig-cap: "Sample Plot"
import matplotlib.pyplot as plt
plt.plot([1, 2, 3], [1, 4, 9])
```
~~~

### Inline R Code

```markdown
The mean is `r mean(c(1,2,3))`.
```

### Chunk Options

~~~markdown
```{r, echo=FALSE, fig.width=6, fig.height=4}
plot(cars)
```
~~~

---

## 11. Wiki-Style Links & Knowledge Base Features

### Wiki Links (Obsidian/Roam/Foam)

```markdown
[[Page Name]]
[[Page Name|Custom Display Text]]
[[Page Name#Heading]]
[[Page Name^block-id]]
![[Embedded Page]]
![[image.png|300x200]]
```

### Block References

```markdown
^unique-block-id

Reference to [[Page#^unique-block-id]]
```

### Tags

```markdown
#tag #multi-word-tag #nested/tag #2024/01/projects
#[[Complex Tag Name]]
```

### Dataview (Obsidian)

~~~markdown
```dataview
TABLE author, rating, finished
FROM #books
WHERE rating > 4
SORT finished DESC
```

`= this.file.name`
`= date(now)`
~~~

---

## 12. MDX (Markdown + JSX)

```jsx
import Button from './Button'
import { Chart } from './Chart'

export const meta = {
  title: 'MDX Document',
  author: 'John'
}

# {meta.title}

<Button onClick={() => alert('Clicked!')}>
  Click me
</Button>

<Chart data={[1, 2, 3]} />

Regular markdown with *React components*.
```

---

## 13. AsciiDoc-Influenced Features

### Admonition Blocks (Alternative Syntax)

```markdown
NOTE: This is a note.

TIP: Helpful tip here.

IMPORTANT: Don't forget this.

WARNING: Be careful!

CAUTION: Critical warning.
```

### Include Directives

```markdown
include::chapter1.md[]
include::code.js[lines=5..10]
```

### Conditional Directives

```markdown
ifdef::env-github[]
This only shows on GitHub.
endif::[]

ifndef::env-github[]
This shows everywhere except GitHub.
endif::[]
```

---

## 14. Mathematical Notation (Extended)

### Display Math Environments

```latex
$$
\begin{align}
a &= b + c \\
d &= e + f + g \\
h &= i
\end{align}
$$

$$
\begin{matrix}
a & b & c \\
d & e & f \\
g & h & i
\end{matrix}
$$

$$
\begin{cases}
x + y = 5 \\
2x - y = 1
\end{cases}
$$
```

### Chemical Equations

```latex
$\ce{2H2 + O2 -> 2H2O}$

$\ce{SO4^2- + Ba^2+ -> BaSO4 v}$
```

### Physics Notation

```latex
$\ket{\psi} = \alpha\ket{0} + \beta\ket{1}$

$\bra{\phi}\ket{\psi}$
```

---

## 15. Diagram Extensions

### PlantUML

~~~markdown
```plantuml
@startuml
!theme plain
actor User
participant "Web Browser" as Browser
participant "Web Server" as Server
database "Database" as DB

User -> Browser: Enter URL
Browser -> Server: HTTP Request
Server -> DB: Query
DB -> Server: Results
Server -> Browser: HTTP Response
Browser -> User: Display Page
@enduml
```
~~~

### Ditaa

~~~markdown
```ditaa
    +--------+   +-------+    +-------+
    |        | --+ ditaa +--> |       |
    |  Text  |   +-------+    |diagram|
    |Document|   |!magic!|    |       |
    |     {d}|   |       |    |       |
    +---+----+   +-------+    +-------+
        :                         ^
        |       Lots of work      |
        +-------------------------+
```
~~~

### Graphviz DOT

~~~markdown
```dot
digraph finite_state_machine {
    rankdir=LR;
    size="8,5"

    node [shape = doublecircle]; S;
    node [shape = point ]; qi

    node [shape = circle];
    qi -> S;
    S  -> q1 [ label = "a" ];
    S  -> S  [ label = "a" ];
    q1 -> S  [ label = "a" ];
    q1 -> q2 [ label = "b" ];
    q2 -> q1 [ label = "b" ];
    q2 -> q2 [ label = "b" ];
}
```
~~~

### Vega-Lite

~~~markdown
```vega-lite
{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "data": {"url": "data.csv"},
  "mark": "bar",
  "encoding": {
    "x": {"field": "category", "type": "nominal"},
    "y": {"field": "value", "type": "quantitative"}
  }
}
```
~~~

---

## 16. Scholarly Markdown

### Abstract Block

```markdown
{abstract}
This paper presents a comprehensive overview of markdown
flavors and their features. We examine standard syntax
and extended capabilities across implementations.
{/abstract}
```

### Author Block

```markdown
{authors}
John Doe^1^, Jane Smith^2^

^1^ University of Examples
^2^ Institute of Documentation
{/authors}
```

### Keywords

```markdown
{keywords}
markdown, documentation, syntax, reference
{/keywords}
```

### DOI/Bibliography

```markdown
[@doi:10.1000/xyz123] shows that markdown is effective.

See [@smith2024; @doe2023] for more information.
```

### Glossary

```markdown
{glossary}
GFM
: GitHub Flavored Markdown

MMD
: MultiMarkdown
{/glossary}
```

---

## 17. Hugo/Jekyll/Static Site Features

### Front Matter (TOML)

```toml
+++
title = "Post Title"
date = 2024-01-01T10:00:00Z
draft = false
tags = ["markdown", "hugo"]
categories = ["documentation"]
+++
```

### Shortcodes

```markdown
{{</* youtube w7Ft2ymGmfc */>}}
{{</* tweet user="xxx" id="xxx" */>}}
{{</* gist user="xxx" id="xxx" */>}}
{{</* figure src="image.jpg" title="Figure 1" */>}}
{{</* highlight go "linenos=table" */>}}
package main
import "fmt"
func main() {
    fmt.Println("Hello")
}
{{</* /highlight */>}}
```

### Jekyll Includes

```liquid
{% include header.html %}
{% include_relative file.md %}
```

### Liquid Templates

```liquid
{% for post in site.posts %}
- [{{ post.title }}]({{ post.url }})
{% endfor %}

{% if page.comments %}
  {% include comments.html %}
{% endif %}
```

---

## 18. Markua (LeanPub)

### Aside

```markdown
A> This is an aside (sidebar).
A> It can span multiple lines.
```

### Blurb

```markdown
B> This is a blurb - a textbox with special styling.
```

### Discussion

```markdown
D> This is a discussion box for exercises or questions.
```

### Error/Warning/Information

```markdown
E> This is an error message.

W> This is a warning.

I> This is an information box.
```

### Quiz

```markdown
{quiz, id: quiz1}
? What is 2 + 2?

a) 3
B) 4
c) 5
d) 6

? Which are markdown flavors?

[X] GFM
[X] CommonMark
[ ] XML
[X] Pandoc
{/quiz}
```

---

## 19. Advanced Table Features

### Column Spanning (some flavors)

```markdown
| Column 1 | Column 2 | Column 3 |
|----------|:--------:|---------:|
| span=2   |          | Right    |
| Left     | Center   | Right    |
```

### MultiMarkdown Tables

```markdown
|             |          Grouping           ||
| First Header | Second Header | Third Header |
| ------------ | :-----------: | -----------: |
| Content      |   *Long Cell*               ||
| Content      |   **Cell**    |         Cell |
| New section  |     More      |         Data |
| And more     | With an escaped '\|'        ||
[Table caption, works in MD Extra too]
```

### Grid Table with Alignment

```markdown
+:-----+:-----:+-----:+
| Left |Center |Right |
+======+=======+======+
| L    |   C   |    R |
+------+-------+------+
| Left |Center |Right |
+------+-------+------+
```

---

## 20. Custom HTML with Markdown

### Details with Markdown

```html
<details markdown="1">
<summary>Click for markdown content</summary>

- This is a **list**
- With _formatting_
- Inside HTML details

```python
# Even code blocks work
print("Hello from details")
```

</details>
```

### Ruby Annotations

```html
<ruby>
漢字<rt>かんじ</rt>
</ruby>

<ruby>
WWW<rt>World Wide Web</rt>
</ruby>
```

### Progress Bars

```html
<progress value="70" max="100">70%</progress>

<meter value="6" min="0" max="10">6 out of 10</meter>
```

---

## 21. Extended Link Features

### Link Attributes

```markdown
[External Link](https://example.com){:target="_blank" rel="noopener"}

[Download](file.pdf){:download="filename.pdf"}
```

### Anchor Links with IDs

```markdown
{#custom-anchor}
### Heading with Custom ID

Jump to [custom anchor](#custom-anchor)
```

### Protocol Links

```markdown
[Email](mailto:user@example.com?subject=Hello)
[Phone](tel:+1234567890)
[SMS](sms:+1234567890?body=Hello)
[FTP](ftp://files.example.com)
```

---

## 22. Typography Extensions

### Small Caps

```html
<span style="font-variant: small-caps;">Small Caps Text</span>
```

```markdown
%{Small Caps}% (some flavors)
```

### Fractions

```markdown
1/2 1/3 2/3 1/4 3/4 1/8 3/8 5/8 7/8
```

### Ordinals

```markdown
1st 2nd 3rd 4th 21st 42nd
```

### Smart Punctuation

```markdown
"Curly quotes" and 'apostrophes'...
— Em dash and – en dash
(C) (R) (TM) (P) +-
```

---

## 23. Metadata & Processing Instructions

### Processing Instructions

```markdown
{frontmatter}
toc: true
numbered: true
lang: en
{/frontmatter}

{mainmatter}

{backmatter}
```

### Parser Directives

~~~markdown
~~~~~~~~~~~~~~~~~~~~~{.python .numberLines startFrom="100"}
def process():
    return "Code with attributes"
~~~~~~~~~~~~~~~~~~~~~
~~~

### Raw LaTeX

```latex
\newpage
\tableofcontents
\listoffigures
\listoftables
```

---

## 24. List Extensions

### Alphabetical Lists

```markdown
a. First item
b. Second item
c. Third item

A. Upper case
B. Continues
C. Through alphabet
```

### Definition Lists (Extended)

```markdown
Apple
:   A fruit
:   A company
    - Makes phones
    - Makes computers
:   A symbolic object

Orange
Citrus
:   Multiple terms, one definition
```

### Interrupted Lists

```markdown
1. First item

<!-- comment breaks list -->

1. New list starts

1. First item

{:.continue}
2. Continues previous list
```

---

## 25. Special Blocks & Environments

### Theorem Environment

```markdown
::: theorem
Let $f$ be a continuous function on $[a,b]$. Then $f$
attains its maximum and minimum values.
:::

::: proof
By the extreme value theorem...
:::

::: lemma
Supporting result here.
:::

::: corollary
Following from the theorem...
:::
```

### Exercise Blocks

```markdown
::: exercise
Prove that $\sqrt{2}$ is irrational.
:::

::: solution
Assume $\sqrt{2} = p/q$ where $p,q$ are integers...
:::
```

---

## 26. Accessibility Features

### Image Descriptions

```markdown
![Alt text](image.jpg "Title"){longdesc="Extended description for screen readers"}
```

### Abbreviation Definitions

```markdown
The HTML specification is maintained by W3C.

*[HTML]: HyperText Markup Language
*[W3C]: World Wide Web Consortium
```

### Language Marking

```html
This is English text. <span lang="es">Esto es español.</span>
<span lang="ja">これは日本語です。</span>
```

---

## 27. Version Control Integration

### Diff Syntax

~~~markdown
```diff
@@ -1,3 +1,3 @@
 Line 1
-Line 2 (removed)
+Line 2 (added)
 Line 3
```
~~~

### Merge Conflicts

```
<<<<<<< HEAD
Current change
=======
Incoming change
>>>>>>> branch-name
```

### Blame Annotations

```
e83c516 (John 2024-01-01) Initial commit
a4f9b32 (Jane 2024-01-02) Fix typo
```

---

## 28. Additional Special Characters

### Box Drawing

```
┌─────────┬─────────┐
│ Cell 1  │ Cell 2  │
├─────────┼─────────┤
│ Cell 3  │ Cell 4  │
└─────────┴─────────┘
```

### Arrows & Symbols

```
← → ↑ ↓ ↔ ↕ ⇐ ⇒ ⇑ ⇓ ⇔ ⇕
✓ ✗ ✔ ✖ ✚ ★ ☆ ♠ ♣ ♥ ♦
① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩
```

### Math Symbols

```
∀ ∃ ∅ ∇ ∈ ∉ ∋ ∏ ∑ ∞
⊂ ⊃ ⊆ ⊇ ∪ ∩ ∧ ∨ ¬ ⊕
```

---

## Summary: Feature Support by Flavor

| Feature | Original | CommonMark | GFM | MMD | Pandoc | Kramdown |
|---------|:--------:|:----------:|:---:|:---:|:------:|:--------:|
| Headings | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Emphasis | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Lists | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Links | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Images | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Code blocks | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Tables | – | – | ✓ | ✓ | ✓ | ✓ |
| Task lists | – | – | ✓ | – | ✓ | – |
| Strikethrough | – | – | ✓ | ✓ | ✓ | ✓ |
| Footnotes | – | – | – | ✓ | ✓ | ✓ |
| Math | – | – | – | ✓ | ✓ | ✓ |
| Definition lists | – | – | – | ✓ | ✓ | ✓ |
| Abbreviations | – | – | – | ✓ | ✓ | ✓ |
| Attributes | – | – | – | ✓ | ✓ | ✓ |
| Div blocks | – | – | – | – | ✓ | – |
| Span elements | – | – | – | – | ✓ | – |
| Superscript | – | – | – | ✓ | ✓ | – |
| Subscript | – | – | – | ✓ | ✓ | – |

---

## Quick Reference Card

| Category | Syntax | Result |
|----------|--------|--------|
| **Headings** | `# H1` `## H2` `### H3` | Heading levels 1-6 |
| **Bold** | `**text**` or `__text__` | **text** |
| **Italic** | `*text*` or `_text_` | *text* |
| **Bold + Italic** | `***text***` | ***text*** |
| **Strikethrough** | `~~text~~` | ~~text~~ |
| **Inline code** | `` `code` `` | `code` |
| **Link** | `[text](url)` | [text](url) |
| **Image** | `![alt](url)` | Embedded image |
| **Blockquote** | `> quote` | Indented quote |
| **Unordered list** | `- item` or `* item` | Bullet list |
| **Ordered list** | `1. item` | Numbered list |
| **Task list** | `- [ ]` / `- [x]` | Checkbox |
| **Horizontal rule** | `---` or `***` | Divider line |
| **Code block** | ` ``` ` or indent 4 spaces | Code block |
| **Table** | `\| col \| col \|` | Table |
| **Footnote** | `[^1]` | Superscript reference |

---

**The golden rule:** Headings, emphasis, lists, links, images, code blocks, and blockquotes work everywhere. Everything else depends on your processor.

1. Basic Syntax (Original Markdown)

Headings

# Heading 1
## Heading 2
### Heading 3
#### Heading 4
##### Heading 5
###### Heading 6

Alternative H1
==============

Alternative H2
--------------

Emphasis

*italic* or _italic_
**bold** or __bold__
***bold italic*** or ___bold italic___
~~strikethrough~~ (GFM extension)

Lists

Unordered:

* Item 1
* Item 2
  * Nested item 2.1
  * Nested item 2.2
    * Deep nested
- Item with dash
+ Item with plus

Ordered:

1. First item
2. Second item
   1. Nested ordered
   2. Another nested
3. Third item
1. Numbers don't need to be sequential

Links & Images

[Inline link](https://example.com "Optional Title")
[Reference link][ref1]
[Implicit reference][]
<https://automatic-link.com>
<email@example.com>

![Alt text](image.jpg "Optional title")
![Reference image][img-ref]

[ref1]: https://example.com "Reference Title"
[Implicit reference]: https://example.com
[img-ref]: image.jpg "Image Reference"

Blockquotes

> Single line quote

> Multi-line quote continues here
> and here

> Nested quotes
>> Can be nested
>>> Multiple levels deep

Code

Inline `code` with backticks

    Code block with 4 spaces
    or tab indentation

```
Fenced code block
Multiple lines
```

```javascript
// Syntax highlighted (GFM)
function hello() {
    console.log("Hello, World!");
}
```

Horizontal Rules

Three or more:

---
Hyphens

***
Asterisks

___
Underscores

2. GitHub Flavored Markdown (GFM)

Tables

| Left-aligned | Center-aligned | Right-aligned |
| :----------- | :------------: | ------------: |
| Cell 1       | Cell 2         | Cell 3        |
| Longer text  | **Bold**       | *Italic*      |

Minimal table:

First Header | Second Header
------------ | -------------
Content Cell | Content Cell

Rendered:

Left-aligned	Center-aligned	Right-aligned
Cell 1	Cell 2	Cell 3
Longer text	Bold	Italic

Task Lists

- [x] Completed task
- [ ] Uncompleted task
- [ ] Another todo
  - [x] Nested completed
  - [ ] Nested uncompleted

Rendered:

[x] Completed task
[ ] Uncompleted task
[ ] Another todo
- [x] Nested completed
- [ ] Nested uncompleted

Username & Issue Mentions

@username (GitHub only)
#123 (Issue reference)
user/repo#123 (Cross-repo issue)

Emoji

:smile: :heart: :thumbsup: :100:
:rocket: :octocat: :+1: :-1:

Syntax Highlighting with Language

```python
def factorial(n):
    """Calculate factorial"""
    if n <= 1:
        return 1
    return n * factorial(n - 1)
```

```diff
- Removed line
+ Added line
! Important change
# Comment
```

Rendered:

def factorial(n):
    """Calculate factorial"""
    if n <= 1:
        return 1
    return n * factorial(n - 1)

- Removed line
+ Added line
! Important change
# Comment

SHA References

16c999e8c71134401a78d4d46435517b2271d6ac
mojombo@16c999e8c71134401a78d4d46435517b2271d6ac
mojombo/github-flavored-markdown@16c999e

3. CommonMark Extensions

Autolinks

www.example.com (some parsers)
https://example.com
ftp://files.example.com

Disallowed Raw HTML (optional)

<script>alert('This may be stripped');</script>
<div class="custom">Safe HTML allowed in some flavors</div>

Entity & Numeric Character References

&nbsp; &amp; &lt; &gt; &quot; &apos;
&#65; &#x41; &#8230;

4. MultiMarkdown Extensions

Metadata Block

Title: Document Title
Author: John Doe
Date: 2024-01-01
Tags: markdown, reference
Base Header Level: 2

Footnotes

Here's a sentence with a footnote[^1].

Here's another with a longer note[^longnote].

Inline footnote^[This is an inline footnote].

[^1]: This is the footnote.

[^longnote]: Here's one with multiple paragraphs.

    Indent paragraphs to include them in the footnote.

    > Even blockquotes in footnotes!

Citations

This is a statement that needs citation[p. 23][#Doe:2024].

Multiple citations[p. 10][#Smith:2023; p. 24][#Doe:2024].

[#Doe:2024]: John Doe. *Sample Book*. 2024.
[#Smith:2023]: Jane Smith. *Another Book*. 2023.

Math (also Pandoc)

Inline math: $E = mc^2$ or \\(a^2 + b^2 = c^2\\)

Display math:
$$
\sum_{i=1}^{n} x_i = \int_{0}^{1} f(x) dx
$$

\\[
\frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
\\]

Abbreviations

HTML is great.
CSS is awesome.

*[HTML]: HyperText Markup Language
*[CSS]: Cascading Style Sheets

Definition Lists

Term 1
:   Definition 1
:   Another definition

Term 2
:   Definition with *inline* **formatting**

Compact Definition
: Brief description

Smart Typography

"Smart quotes" and 'single quotes'
En-dash -- and em-dash ---
Ellipsis...

Cross-references

See [](#heading-1) for more info.
As discussed in [](#fig:example).

![Example Figure][fig:example]

[fig:example]: image.jpg "Example" width=500px height=300px

5. Pandoc Markdown Extensions

Div Blocks

::: {.note #special-note}
This is a special note block with class and id.
:::

::: warning
This is a warning block.
:::

::: {.sidebar}
Sidebar content here
:::

Span Elements

This is [special text]{.highlight #text-id} inline.

[Small caps]{.smallcaps} text.

Line Blocks

| The limerick packs laughs anatomical
| In space that is quite economical.
|    But the good ones I've seen
|    So seldom are clean
| And the clean ones so seldom are comical

Fancy Lists

(1) First item
(2) Second item
    a. Sub-item
    b. Another sub
        i. Deep nesting

#. Auto-numbered
#. Continues numbering

i. Roman numerals
ii. Continue
    A. Upper letters
    B. More items

Example lists:
(@) First example
(@) Second example

Later reference to example (@).

Grid Tables

+---------------+---------------+--------------------+
| Fruit         | Price         | Advantages         |
+===============+===============+====================+
| Bananas       | $1.34         | - built-in wrapper |
|               |               | - bright color     |
+---------------+---------------+--------------------+
| Oranges       | $2.10         | - cures scurvy     |
|               |               | - tasty            |
+---------------+---------------+--------------------+

Pipe Tables (simpler)

| Right | Left | Default | Center |
|------:|:-----|---------|:------:|
|   12  |  12  |    12   |   12   |
|  123  |  123 |   123   |  123   |
|    1  |    1 |     1   |    1   |

Superscript and Subscript

H~2~O is water.
X^2^ is X squared.
^superscript^ and ~subscript~

Inline Code Attributes

`code`{.python}
`var x = 5;`{#mycode .javascript .numberLines startFrom="100"}

Raw Blocks

```{=html}
<div class="custom-html">
  Raw HTML preserved exactly
</div>
```

```{=latex}
\begin{align}
  E &= mc^2
\end{align}
```

```{=mediawiki}
{{Template|arg=value}}
```

YAML Metadata Block

---
title: Complete Reference
subtitle: Every Markdown Feature
author:
  - name: John Doe
    affiliation: University
  - name: Jane Smith
date: 2024-01-01
abstract: |
  This is a multi-line
  abstract in YAML.
tags: [markdown, documentation]
keywords:
  - markdown
  - reference
lang: en-US
toc: true
toc-depth: 3
numbersections: true
---

Native Spans and Divs

<div custom="attribute">
Native div with attributes
</div>

<span class="custom">Native span</span>

6. Extended Features (Various Flavors)

Admonitions/Callouts

!!! note "Optional Title"
    This is a note admonition.

!!! warning
    This is a warning without title.

!!! danger "Critical"
    Important danger message.

!!! tip
    Helpful tip here.

!!! important
    Important information.

!!! example "Code Example"
    ```python
    print("Hello")
    ```

GitHub-style callouts:

> [!NOTE]
> GitHub-style callout

> [!WARNING]
> Another style of callout

> [!TIP]
> Helpful information

> [!IMPORTANT]
> Crucial information

> [!CAUTION]
> Be careful here

Keyboard Keys

Press <kbd>Ctrl</kbd> + <kbd>C</kbd> to copy.
<kbd>⌘</kbd> + <kbd>V</kbd> on Mac.

++ctrl+alt+del++ (some flavors)

Rendered:

Press Ctrl + C to copy.
⌘ + V on Mac.

Mark/Highlight

==Highlighted text== (some flavors)
<mark>HTML mark element</mark>
{==highlighted==} (critic markup)

Rendered:

HTML mark element

Insert/Delete (Critic Markup)

{++inserted text++}
{--deleted text--}
{~~old~>new~~}
{>>comment<<}
{==highlight==}{>>with comment<<}

Details/Summary

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

Hidden content here with:
- Lists
- **Formatting**
- Etc.

</details>

<details open>
<summary>Expanded by default</summary>
This is visible initially.
</details>

Rendered:

Click to expand

Hidden content here with:

Lists
Formatting
Etc.

[[TOC]] (some flavors)
[TOC] (other flavors)
{:toc} (kramdown)

Include Files

<<[file.md]
<<(file.md)
{{file.md}}
!include file.md
{! file.md !}

Diagrams

```mermaid
graph LR
    A[Start] --> B{Decision}
    B -->|Yes| C[Do this]
    B -->|No| D[Do that]
    C --> E[End]
    D --> E
```

```plantuml
@startuml
Alice -> Bob: Hello
Bob --> Alice: Hi!
@enduml
```

```graphviz
digraph G {
    A -> B;
    B -> C;
    C -> A;
}
```

Custom Containers

::: {.theorem #pythagorean}
**Pythagorean Theorem**: $a^2 + b^2 = c^2$
:::

::: note
Custom note container
:::

::: {.callout-note}
## Note Title
Note content
:::

Attributes on Elements

![](image.jpg){width=50% height=30px}

[Link](url.com){.external target="_blank"}

Paragraph with attributes.
{: .custom-class #custom-id}

Hard Line Breaks

Line ending with two spaces
creates a hard break.

Line ending with backslash\
also creates a hard break (some flavors).

Video Embeds (Some Flavors)

![](video.mp4)
![](https://youtube.com/watch?v=id)

@[youtube](dQw4w9WgXcQ)

Special Lists

Term
  ~ Definition using tilde

Tight list:
* item1
* item2

Loose list:

* item1

* item2

7. Edge Cases & Special Characters

Escaping

\*Not italic\*
\`Not code\`
\[Not a link\](not a url)
\# Not a heading
\| Not a table
\1. Not a list

Special Characters

&copy; &trade; &reg; &deg; &plusmn; &ne; &le; &ge;
&rarr; &larr; &uarr; &darr; &harr;
&frac12; &frac34; &infin; &sum; &prod;

Rendered:

Zero-Width Characters

Zero&#8203;Width&#8203;Space
Word&shy;Break&shy;Hint

Nested Structures

> Blockquote with:
> - List item 1
> - List item 2
>   ```python
>   # code in list in quote
>   print("nested")
>   ```
>   > Nested quote in list
>
> 1. Ordered in quote
> 2. More ordered
>
> | Table | In | Quote |
> |-------|----|----|
> | Works | In | Some |

Complex Nesting

1. List with paragraph

   Multiple paragraph in list item.

   > Quote in list

code in list


2. Another item
- [ ] Task in ordered list
- [x] Completed

Unicode & Emoji

📝 ✨ 🚀 💻 🎯 ⚡ 🔥 ✅ ❌ ⚠️
α β γ δ ε ζ η θ
© ® ™ • · × ÷ ±

Comments

<!-- HTML comment -->
[//]: # (This is also a comment)
[//]: <> (Another comment style)
[comment]: <> (Yet another)

8. Kramdown Specific

Block Attributes

{: .class #id key="value"}
This paragraph has attributes.

> Block quote with attributes.
{: .pullquote}

Options

{::options parse_block_html="true" /}
{::options auto_ids="false" /}

No Markdown

{::nomarkdown}
This *won't* be **parsed**.
{:/}

Comments

{::comment}
This is a kramdown comment.
{:/comment}

9. Markdown Extra

Special Attributes

Header {#header-id .header-class}
================================

[link](url){#link-id .link-class}

Fenced Code Attributes

~~~ {.python #mycode .numberLines startFrom="10"}
def hello():
    print("Hi")


### Markdown Inside HTML

```html
<div markdown="1">
This is *markdown* inside **HTML**.
</div>

<div markdown="block">
- List inside HTML
- Another item
</div>
```

### Backslash Escapes

```markdown
\\ \` \* \_ \{ \} \[ \] \( \) \# \+ \- \. \!
```

---

## 10. R Markdown / Quarto

### Code Chunks

~~~markdown
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

```{python}
#| label: fig-plot
#| fig-cap: "Sample Plot"
import matplotlib.pyplot as plt
plt.plot([1, 2, 3], [1, 4, 9])
```

Inline R Code

The mean is `r mean(c(1,2,3))`.

Chunk Options

```{r, echo=FALSE, fig.width=6, fig.height=4}
plot(cars)
```

11. Wiki-Style Links & Knowledge Base Features

Wiki Links (Obsidian/Roam/Foam)

[[Page Name]]
[[Page Name|Custom Display Text]]
[[Page Name#Heading]]
[[Page Name^block-id]]
![[Embedded Page]]
![[image.png|300x200]]

Block References

^unique-block-id

Reference to [[Page#^unique-block-id]]

Dataview (Obsidian)

```dataview
TABLE author, rating, finished
FROM #books
WHERE rating > 4
SORT finished DESC
```

`= this.file.name`
`= date(now)`

12. MDX (Markdown + JSX)

import Button from './Button'
import { Chart } from './Chart'

export const meta = {
  title: 'MDX Document',
  author: 'John'
}

# {meta.title}

<Button onClick={() => alert('Clicked!')}>
  Click me
</Button>

<Chart data={[1, 2, 3]} />

Regular markdown with *React components*.

13. AsciiDoc-Influenced Features

Admonition Blocks (Alternative Syntax)

NOTE: This is a note.

TIP: Helpful tip here.

IMPORTANT: Don't forget this.

WARNING: Be careful!

CAUTION: Critical warning.

Include Directives

include::chapter1.md[]
include::code.js[lines=5..10]

Conditional Directives

ifdef::env-github[]
This only shows on GitHub.
endif::[]

ifndef::env-github[]
This shows everywhere except GitHub.
endif::[]

14. Mathematical Notation (Extended)

Display Math Environments

$$
\begin{align}
a &= b + c \\
d &= e + f + g \\
h &= i
\end{align}
$$

$$
\begin{matrix}
a & b & c \\
d & e & f \\
g & h & i
\end{matrix}
$$

$$
\begin{cases}
x + y = 5 \\
2x - y = 1
\end{cases}
$$

Chemical Equations

$\ce{2H2 + O2 -> 2H2O}$

$\ce{SO4^2- + Ba^2+ -> BaSO4 v}$

Physics Notation

$\ket{\psi} = \alpha\ket{0} + \beta\ket{1}$

$\bra{\phi}\ket{\psi}$

15. Diagram Extensions

PlantUML

```plantuml
@startuml
!theme plain
actor User
participant "Web Browser" as Browser
participant "Web Server" as Server
database "Database" as DB

User -> Browser: Enter URL
Browser -> Server: HTTP Request
Server -> DB: Query
DB -> Server: Results
Server -> Browser: HTTP Response
Browser -> User: Display Page
@enduml
```

Ditaa

```ditaa
    +--------+   +-------+    +-------+
    |        | --+ ditaa +--> |       |
    |  Text  |   +-------+    |diagram|
    |Document|   |!magic!|    |       |
    |     {d}|   |       |    |       |
    +---+----+   +-------+    +-------+
        :                         ^
        |       Lots of work      |
        +-------------------------+
```

Graphviz DOT

```dot
digraph finite_state_machine {
    rankdir=LR;
    size="8,5"

    node [shape = doublecircle]; S;
    node [shape = point ]; qi

    node [shape = circle];
    qi -> S;
    S  -> q1 [ label = "a" ];
    S  -> S  [ label = "a" ];
    q1 -> S  [ label = "a" ];
    q1 -> q2 [ label = "b" ];
    q2 -> q1 [ label = "b" ];
    q2 -> q2 [ label = "b" ];
}
```

Vega-Lite

```vega-lite
{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "data": {"url": "data.csv"},
  "mark": "bar",
  "encoding": {
    "x": {"field": "category", "type": "nominal"},
    "y": {"field": "value", "type": "quantitative"}
  }
}
```

16. Scholarly Markdown

Abstract Block

{abstract}
This paper presents a comprehensive overview of markdown
flavors and their features. We examine standard syntax
and extended capabilities across implementations.
{/abstract}

Author Block

{authors}
John Doe^1^, Jane Smith^2^

^1^ University of Examples
^2^ Institute of Documentation
{/authors}

Keywords

{keywords}
markdown, documentation, syntax, reference
{/keywords}

DOI/Bibliography

[@doi:10.1000/xyz123] shows that markdown is effective.

See [@smith2024; @doe2023] for more information.

Glossary

{glossary}
GFM
: GitHub Flavored Markdown

MMD
: MultiMarkdown
{/glossary}

17. Hugo/Jekyll/Static Site Features

Front Matter (TOML)

+++
title = "Post Title"
date = 2024-01-01T10:00:00Z
draft = false
tags = ["markdown", "hugo"]
categories = ["documentation"]
+++

Shortcodes

{{</* youtube w7Ft2ymGmfc */>}}
{{</* tweet user="xxx" id="xxx" */>}}
{{</* gist user="xxx" id="xxx" */>}}
{{</* figure src="image.jpg" title="Figure 1" */>}}
{{</* highlight go "linenos=table" */>}}
package main
import "fmt"
func main() {
    fmt.Println("Hello")
}
{{</* /highlight */>}}

Jekyll Includes

{% include header.html %}
{% include_relative file.md %}

Liquid Templates

{% for post in site.posts %}
- [{{ post.title }}]({{ post.url }})
{% endfor %}

{% if page.comments %}
  {% include comments.html %}
{% endif %}

18. Markua (LeanPub)

Aside

A> This is an aside (sidebar).
A> It can span multiple lines.

Blurb

B> This is a blurb - a textbox with special styling.

Discussion

D> This is a discussion box for exercises or questions.

Error/Warning/Information

E> This is an error message.

W> This is a warning.

I> This is an information box.

Quiz

{quiz, id: quiz1}
? What is 2 + 2?

a) 3
B) 4
c) 5
d) 6

? Which are markdown flavors?

[X] GFM
[X] CommonMark
[ ] XML
[X] Pandoc
{/quiz}

19. Advanced Table Features

Column Spanning (some flavors)

| Column 1 | Column 2 | Column 3 |
|----------|:--------:|---------:|
| span=2   |          | Right    |
| Left     | Center   | Right    |

MultiMarkdown Tables

|             |          Grouping           ||
| First Header | Second Header | Third Header |
| ------------ | :-----------: | -----------: |
| Content      |   *Long Cell*               ||
| Content      |   **Cell**    |         Cell |
| New section  |     More      |         Data |
| And more     | With an escaped '\|'        ||
[Table caption, works in MD Extra too]

Grid Table with Alignment

+:-----+:-----:+-----:+
| Left |Center |Right |
+======+=======+======+
| L    |   C   |    R |
+------+-------+------+
| Left |Center |Right |
+------+-------+------+

20. Custom HTML with Markdown

Details with Markdown

<details markdown="1">
<summary>Click for markdown content</summary>

- This is a **list**
- With _formatting_
- Inside HTML details

```python
# Even code blocks work
print("Hello from details")

```

Ruby Annotations

<ruby>
漢字<rt>かんじ</rt>
</ruby>

<ruby>
WWW<rt>World Wide Web</rt>
</ruby>

Progress Bars

<progress value="70" max="100">70%</progress>

<meter value="6" min="0" max="10">6 out of 10</meter>

21. Extended Link Features

Link Attributes

[External Link](https://example.com){:target="_blank" rel="noopener"}

[Download](file.pdf){:download="filename.pdf"}

Anchor Links with IDs

{#custom-anchor}
### Heading with Custom ID

Jump to [custom anchor](#custom-anchor)

Protocol Links

[Email](mailto:user@example.com?subject=Hello)
[Phone](tel:+1234567890)
[SMS](sms:+1234567890?body=Hello)
[FTP](ftp://files.example.com)

22. Typography Extensions

Small Caps

<span style="font-variant: small-caps;">Small Caps Text</span>

%{Small Caps}% (some flavors)

Fractions

1/2 1/3 2/3 1/4 3/4 1/8 3/8 5/8 7/8

Ordinals

1st 2nd 3rd 4th 21st 42nd

Smart Punctuation

"Curly quotes" and 'apostrophes'...
— Em dash and – en dash
(C) (R) (TM) (P) +-

23. Metadata & Processing Instructions

Processing Instructions

{frontmatter}
toc: true
numbered: true
lang: en
{/frontmatter}

{mainmatter}

{backmatter}

Parser Directives

~~~~~~~~~~~~~~~~~~~~~{.python .numberLines startFrom="100"}
def process():
    return "Code with attributes"


### Raw LaTeX

```latex
\newpage
\tableofcontents
\listoffigures
\listoftables
```

---

## 24. List Extensions

### Alphabetical Lists

```markdown
a. First item
b. Second item
c. Third item

A. Upper case
B. Continues
C. Through alphabet
```

### Definition Lists (Extended)

```markdown
Apple
:   A fruit
:   A company
    - Makes phones
    - Makes computers
:   A symbolic object

Orange
Citrus
:   Multiple terms, one definition
```

### Interrupted Lists

```markdown
1. First item

<!-- comment breaks list -->

1. New list starts

1. First item

{:.continue}
2. Continues previous list
```

---

## 25. Special Blocks & Environments

### Theorem Environment

```markdown
::: theorem
Let $f$ be a continuous function on $[a,b]$. Then $f$
attains its maximum and minimum values.
:::

::: proof
By the extreme value theorem...
:::

::: lemma
Supporting result here.
:::

::: corollary
Following from the theorem...
:::
```

### Exercise Blocks

```markdown
::: exercise
Prove that $\sqrt{2}$ is irrational.
:::

::: solution
Assume $\sqrt{2} = p/q$ where $p,q$ are integers...
:::
```

---

## 26. Accessibility Features

### Image Descriptions

```markdown
![Alt text](image.jpg "Title"){longdesc="Extended description for screen readers"}
```

### Abbreviation Definitions

```markdown
The HTML specification is maintained by W3C.

*[HTML]: HyperText Markup Language
*[W3C]: World Wide Web Consortium
```

### Language Marking

```html
This is English text. <span lang="es">Esto es español.</span>
<span lang="ja">これは日本語です。</span>
```

---

## 27. Version Control Integration

### Diff Syntax

~~~markdown
```diff
@@ -1,3 +1,3 @@
 Line 1
-Line 2 (removed)
+Line 2 (added)
 Line 3
```

Merge Conflicts

<<<<<<< HEAD
Current change
=======
Incoming change
>>>>>>> branch-name

Blame Annotations

e83c516 (John 2024-01-01) Initial commit
a4f9b32 (Jane 2024-01-02) Fix typo

28. Additional Special Characters

Box Drawing

┌─────────┬─────────┐
│ Cell 1  │ Cell 2  │
├─────────┼─────────┤
│ Cell 3  │ Cell 4  │
└─────────┴─────────┘

Arrows & Symbols

← → ↑ ↓ ↔ ↕ ⇐ ⇒ ⇑ ⇓ ⇔ ⇕
✓ ✗ ✔ ✖ ✚ ★ ☆ ♠ ♣ ♥ ♦
① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩

Math Symbols

∀ ∃ ∅ ∇ ∈ ∉ ∋ ∏ ∑ ∞
⊂ ⊃ ⊆ ⊇ ∪ ∩ ∧ ∨ ¬ ⊕

Summary: Feature Support by Flavor

Feature	Original	CommonMark	GFM	MMD	Pandoc	Kramdown
Headings	✓	✓	✓	✓	✓	✓
Emphasis	✓	✓	✓	✓	✓	✓
Lists	✓	✓	✓	✓	✓	✓
Links	✓	✓	✓	✓	✓	✓
Images	✓	✓	✓	✓	✓	✓
Code blocks	✓	✓	✓	✓	✓	✓
Tables	–	–	✓	✓	✓	✓
Task lists	–	–	✓	–	✓	–
Strikethrough	–	–	✓	✓	✓	✓
Footnotes	–	–	–	✓	✓	✓
Math	–	–	–	✓	✓	✓
Definition lists	–	–	–	✓	✓	✓
Abbreviations	–	–	–	✓	✓	✓
Attributes	–	–	–	✓	✓	✓
Div blocks	–	–	–	–	✓	–
Span elements	–	–	–	–	✓	–
Superscript	–	–	–	✓	✓	–
Subscript	–	–	–	✓	✓	–

Quick Reference Card

Category	Syntax	Result
Headings	`# H1` `## H2` `### H3`	Heading levels 1-6
Bold	`text` or `__text__`	text
Italic	`text` or `_text_`	text
Bold + Italic	`*text*`	text
Strikethrough	`~~text~~`	~~text~~
Inline code	`code`	`code`
Link	`[text](url)`	text
Image	`![alt](url)`	Embedded image
Blockquote	`> quote`	Indented quote
Unordered list	`- item` or `* item`	Bullet list
Ordered list	`1. item`	Numbered list
Task list	`- [ ]` / `- [x]`	Checkbox
Horizontal rule	`---` or `***`	Divider line
Code block	``` or indent 4 spaces	Code block
Table	`\| col \| col \|`	Table
Footnote	`[^1]`	Superscript reference

The golden rule: Headings, emphasis, lists, links, images, code blocks, and blockquotes work everywhere. Everything else depends on your processor.

Saturday, 6 December 2025

, & Illya Starikov

Technology