Footnotes

Footnotes are a way in printed documents to add more information outside of the main flow of text. They don’t apply well to online experiences, especially on mobile devices.

[2]

As footnote labels, you can use numbers [1], labels [2], or you can use automatic labeling [3]

rst

.. [#label]_ As footnote labels, you can use numbers [1]_, labels [#label]_,
   or you can use automatic labeling [#]_.