Is there a list of possible markdown for Patchwork?

Patchwork messages can be written with markdown, but what specific flavor or dialect of markdown? I want a style guide!

Here you go!

***
Emphasis, aka italics, with *asterisks* or _underscores_.

Strong emphasis, aka bold, with **asterisks** or __underscores__.

Combined emphasis with **asterisks and _underscores_**.

Strikethrough uses two tildes. ~~Scratch this.~~

1. First ordered list item
2. Another item
  * Unordered sub-list. 
1. Actual numbers don't matter, just that it's a number
   1. Ordered sub-list
4. And another item.  

   Some text that should be aligned with the above item.

* Unordered list can use asterisks
- Or minuses
+ Or pluses

[I'm an inline-style link](https://www.google.com)

[I'm a reference-style link][Arbitrary case-insensitive reference text]

[You can use numbers for reference-style link definitions][1]

Or leave it empty and use the [link text itself]

URLs and URLs in angle brackets will automatically get turned into links. 
http://www.example.com or <http://www.example.com> and sometimes 
example.com (but not on Github, for example).

Some text to show that the reference links can follow later.

arbitrary case-insensitive reference text]: https://www.mozilla.org
[1]: http://slashdot.org
[link text itself]: http://www.reddit.com

The above yields:

Emphasis, aka italics, with asterisks or underscores.

Strong emphasis, aka bold, with asterisks or underscores.

Combined emphasis with asterisks and underscores.

Strikethrough uses two tildes. Scratch this.

1. First ordered list item
2. Another item
   • Unordered sub-list.
3. Actual numbers don't matter, just that it's a number
   1. Ordered sub-list

4. And another item.

   Some text that should be aligned with the above item.

• Unordered list can use asterisks

• Or minuses

• Or pluses

I'm an inline-style link

I'm a reference-style link

You can use numbers for reference-style link definitions

Or leave it empty and use the link text itself

URLs and URLs in angle brackets will automatically get turned into links. http://www.example.com or http://www.example.com and sometimes example.com (but not on Github, for example).

Some text to show that the reference links can follow later.

Sources

This answer was taken almost verbatim from @nanomonkey's fantastic answer on Patchwork.