Complex footnotes
[1] will be "2" (manually numbered), [2] will be "3" (anonymous auto-numbered), and [3] will be "1" (labeled auto-numbered).
[1] This footnote is labeled manually, so its number is fixed.
[2] This footnote will be labeled "3". It is the second auto-numbered footnote, but footnote label "2" is already used.
[3] This autonumber-labeled footnote will be labeled "1". It is the first auto-numbered footnote and no other footnote with label "1" exists. The order of the footnotes is used to determine numbering, not the order of the footnote references.