Can I write footnotes as I do cite references?

Question

Is there a package out there that will allow me to write my footnotes not inline, but in separate file, and them simply refer to their keys?

E.g., instead of writing this:

My main text body\footnote{Really long footnote...
....
...
} text continues here.

I would like to be able to do something like this:

My main text body\footnote{a} text continues here.


\Footnote{A}{Really long footnote...
....
...}

Answer 1

Yes, there is at least one package: sep­foot­notes.

Abstract from the documentation:

The sepfootnotes package supports footnotes and endnotes from separate files. Basically, it provides \sepfootnotecontent and \sepfootnote: the former defines the content of a note; the latter typesets that note.

You can define your own footnote or endnote apparatus, as well.

Example, basically also taken from the documentation:

“How to typeset a footnote to Plato and an endnote to Homer from a separate file in no particular order”:

• document.tex:

  \documentclass{article}
  \usepackage{sepfootnotes}
  \newfootnotes{F}
  \newendnotes{E}
  \input{mynotes}
  \begin{document}
  This was first brought up by the great Plato.\Enote{Plato}
  But an antecedent is to be found in Homer.\Fnote{Homer}
  \section*{Notes}
  \theEnotes
  \end{document}
  

• mynotes.tex:

  \Fnotecontent{Homer}{The greatest of ancient poets.}
  \Enotecontent{Plato}{Socrates’s pupil.}