D.2.3 Footnotes

Footnotes => int32[n-footnotes] Footnote*[n-footnotes]
Footnote => Value[text] (58 | 31 Value[marker]) int32[show]

Each footnote has text and an optional custom marker (such as ‘*’).

The syntax for Value would allow footnotes (and their markers) to reference other footnotes, but in practice this doesn’t work.

show is a 32-bit signed integer. It is positive to show the footnote or negative to hide it. Its magnitude is often 1, and in other cases tends to be the number of references to the footnote. It is safe to write 1 to show a footnote and -1 to hide it.