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
.



We support inline notes too as ASIDE blocks after the active paragraph:

.
Here is an inline note.^[Inlines notes are easier to write, since
you don't have to pick an identifier and move down to type the
note.]

Followed by yet another paragraph of regular text.
.
xxx
.




Duplicate footnotes:

.
Note [^xxxxx].

Also note [^xxxxx]

[^xxxxx]: foo

Tail A.

Tail B.
.
xxx
.


Now what should happen when a footnote is referenced AFTER it's been defined? Point back at the EARLIER footnote block, surely!

.
[^xxxxx] [^yyyyy]

[^xxxxx]: foo
    xyz

[^yyyyy]: foo
   abc

Intermission.

Recurring: note[^yyyyy].

And the other dude[^xxxxx] too.
.
xxx
.