Foo [bar] [1].
Foo [bar][1].
Foo [bar]
[1].
[1]: /url/ "Title"
With [embedded [brackets]] [b].
Indented [once][].
Indented [twice][].
Indented [thrice][].
Indented [four][] times.
[once]: /url
[twice]: /url
[thrice]: /url
[four]: /url
[b]: /url/