As demanded in another thread, I’ll start here a short Markdown “cheat sheet” with some shortcuts you can use in your posts. Feel free to add stuff. 
0. Introduction
Discourse changes some chars into formats. For example it turns the * at the beginning of a new line/paragraph into a bullet list. If you would like to prevent Discourse from this, just put a backslash \ before the char, in the example: \* This leads to: *. If you would like to print the backlash \, use two of them: \\
1. Fonts
This code:
Text attributes _italic_, *italic*, __bold__, **bold**,
`monospace/preformatted text`, ~~strikethrough~~
(note that there are two _ before and after bold))
produces this:
Text attributes italic, italic, bold, bold,
monospace/preformatted text, strikethrough
2. Paragraphs:
Two spaces at the end of a line (like in this one) leave a
line break.
The lines of quotes are starting with >. So this:
> This is a quote
produces this output:
This is a quote
3. Lists
This code:
Bullet list:
* Franklin
* Ransome
* Delores
Numbered list:
1. Franklin
2. Ransome
3. Delores
produces this:
Bullet list:
- Franklin
- Ransome
- Delores
Numbered list:
- Franklin
- Ransome
- Delores
Notes:
For bullet lists you can use + or - instead of *.
For numbered lists you can use parentheses instead of the dots:
Numbered list:
1) Franklin
2) Ransome
3) Delores
4. Links
This code:
[Wikipedia article](https://en.wikipedia.org/wiki/Markdown)
produces this:
5. Lines
You can produce a line with and empty paragraph following three -. So this:
---
produces this:
6. Headings:
This code:
# Heading
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut
## Sub-heading
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut
### Sub-sub-heading
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut
leads to this:
Heading
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut
Sub-heading
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut
Sub-sub-heading
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut
Note: You can use the following code as an alternative:
A heading
---
Another heading
===
7. Tables
This code:
| Country | Percent | Remark |
| -------------- |:-------:| ------:|
| United States | 30.3% | First |
| Germany | 20.1% | Second |
| United Kingdom | 11.5% | Third |
produces this result:
| Country | Percent | Remark |
|---|---|---|
| United States | 30.3% | First |
| Germany | 20.1% | Second |
| United Kingdom | 11.5% | Third |
Note: In the second row:
|: --- :| means: center the cell content
--- :| means: align the cell content right
You can insert as much - and spaces as you like. This would be also valid:
| Country | Percent | Remark |
| --- |:---:| ---:|
| United States | 30.3% | First |
| Germany | 20.1% | Second |
| United Kingdom | 11.5% | Third |
8. Code blocks
This code with backticks:
```
var hello = "hello world";
print(hello);
```
produces this output:
var hello = "hello world";
print(hello);
Note: Discourse tries to recognize the programming language.
9. Shortcuts
If you enter an interrogation mark, several keyboard shortcuts are shown:
Yeah, thanks, [Alt gr] is the same on italian layout, but the combination doesn’t work and still I don’t see any symbol like that… Maybe you know its name? Or if there are other ways to obtain the same result? Every time I want to do that I need to copy those wave-like characters from here.