Here's a [reference link][1].

[1]: http://parsedown.org

Here's [one][2] on the next line.
[2]: http://parsedown.org

Here's [one][3] with a different URL.

[3]: http://parsedown.org/tests/

Here's [one][website] with a semantic name.

[website]: http://parsedown.org

Here's [one]
[website] with definition name on the next line.

Here's [one][404] with no definition.

Here's an image: ![Markdown Logo][image]

[image]: /md.png

Here's an [implicit one].

[implicit one]: http://google.com

Here's an [implicit one][] with an empty link definition.

Here's a [multiline
one][website] defined on 2 lines.