Pandoc example:
.
Here is a footnote reference,[^1] and another.[^longnote]

[^1]: Here is the footnote.

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

    Subsequent paragraphs are indented to show that they
belong to the previous footnote.

        { some.code }

    The whole paragraph can be indented, or just the first
    line.  In this way, multi-paragraph footnotes work like
    multi-paragraph list items.

This paragraph won't be part of the note, because it
isn't indented.

This paragraph won't be part of the note neither, because it
isn't indented.
.
xxx
.


Duplicate footnotes:
.
[^xxxxx] [^xxxxx]

[^xxxxx]: foo
.
xxx
.



They could terminate each other:

.
[^1][^2][^3]

[^1]: foo
[^2]: bar
[^3]: baz
.
xxx
.