Markdown footnotes
A footnote is a marker in the text and a definition somewhere else in the file. The renderer collects the definitions, numbers them and puts them at the bottom with links back.
What usually goes wrong
- Not part of CommonMark. GitHub, Obsidian and most static site generators support footnotes; chat apps and simple renderers show the brackets as text.
- The label is an identifier, not the number. Renderers number footnotes in the order they appear in the text, so
[^1]can come out as 3. - A definition with no matching marker renders nowhere, silently.