How to disable plain footnote references?

Question

I want to write some text including sequences like [123] in an org-mode text file, but this is automatically turned into a footnote reference. This plain numeric footnote is not recommended anyway. How can I turn off this footnote reference type completely?

There's an answer on the Unix SE based on this thread from 2010, but the solution doesn't work: with #+DISABLE_PLAIN_FOOTNOTES: some arbitrary text in the org file the footnote reference is still created in the buffer.

I'm not sure if this configuration is supposed to depend on the custom .emacs function, but adding that returns an warning:

Warning (initialization): An error occurred while loading `~/.emacs.d/init.el':
Symbol's value as variable is void: org-export-inbuffer-options-extra

Can the plain numeric footnote reference type be disabled?

Answer 1

You can redefine the footnote regular expressions to convince org-mode not to use the [n] markers as footnotes. A little bit of testing suggests that you want to change org-footnote-definition-re:

Documentation: Regular expression matching the definition of a footnote.

and org-footnote-re:

Documentation: Regular expression for matching footnotes.

You'll want to change the regexps as follows:

(setq org-footnote-definition-re "^\\[fn:[-_[:word:]]+\\]"
      org-footnote-re            (concat "\\[\\(?:fn:\\([-_[:word:]]+\\)?:"
                                         "\\|"
                                         "\\(fn:[-_[:word:]]+\\)\\)"))

I simply removed the regexp to match the [n] format. It works fine for me. Side note: the concat stuff is to make the regexp easier to read, at least for me.

Answer 2

The current development version of Org (what will eventually be org-9) requires footnotes to be prefixed with fn, i.e. [n] footnotes are not supported.

See commit 3699558452077 for the updated documentation (related commits: 0, 1, 2, 3, 4, 5).

This work was done by Nicolas Goaziou.