How can I make multiple references to the same footnote?

Question

I am using the memoir class.

In some parts of the page, there are multiple spots that need to be annotated with the same footnote.

Lorem ipsum dolor[1] sit amet, consectetur adipiscing elit[2], sed do eiusmod tempor incididunt ut labore et dolore[1] magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor[1] in reprehenderit in voluptate velit esse cillum dolore[1] eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

---

1: See Appendix on dolors.

2: See Appendix on elites.

Currently, I am manually specifying the footnotes, such as ipsum dolor\footnote[1]{See \emph{Appendix on dolors}.} sit amet. Then I have to manually add the other footnote marks: labore et dolore\textsuperscript{1} magna aliqua

But I don't want to manually keep track of what number is what footnote. They get moved around a lot and I keep forgetting. Besides, I shouldn't have to manually keep track of the numbering, Latex should do it for me.

What command can I use to reference the same footnote multiple times, so that the footnotes are automatically numbered?

Answer 1

Using Andrews MWE and adding some Heiko magic:

\documentclass{memoir}
\usepackage[height=30mm]{geometry}%
\usepackage{refcount}
\begin{document}
  One footnote\footnote{A wonderful footnote!\label{foot}}
  and a second one\footnote{A less wonderful footnote!\label{toe}}.

  The last footnote, \ref{foot}, is really nice. I like
  footnote~\ref{foot} more than footnote \ref{toe}. Here is another
  footnote with the first footnote marker\footnotemark[\getrefnumber{foot}]
  and a second footnote with the second foot note
  marker\footnotemark[\getrefnumber{toe}].

\end{document}

The point is that \ref{...} gives number + \hbox{}, thus \footnotemark does not like it as it expects a number.

The solution probably fails if something other than numbers are used to mark footnotes.

Note how the \label have been added inside the footnotes.

Answer 2

It really ought to be possible to do what you want using the standard \label and \ref commands, however, this does not work because \footnote does not set \@currentlabel which is what LaTeX uses to "remember" the last label.

The obvious fix is to make \footnote remember the last label used, which it calls \@thefnmark. You can do this using the \apptocmd from the etoolbox package:

\makeatletter
\apptocmd{\@footnotetext}{\def\@currentlabel{\@thefnmark}}{}{}
\makeatother

(It turns out that \@footnotetext is the thing to change.) Here's a full MWE:

together with the accompanying code:

\documentclass{memoir}
\usepackage[height=30mm]{geometry}%
\usepackage{etoolbox}
\makeatletter
\apptocmd{\@footnotetext}{\def\@currentlabel{\@thefnmark}}{}{}
\newcommand\footnoteref[1]{\ifcsmacro{r@#1}{\footnotemark[\ref{#1}]}{$^{??}$}}
\makeatother
\begin{document}
  One footnote\footnote{A wonderful footnote!}\label{foot}
  and a second one\footnote{A less wonderful footnote!}\label{toe}.

  The last footnote, \ref{foot}, is really nice. I like
  footnote~\ref{foot} more than footnote \ref{toe}. Here is another
  footnote with the first footnote marker\footnoteref{foot}
  and a second footnote with the second foot note
  marker\footnoteref{toe}.
\end{document}

Edit The macro \footnoteref is convenient for placing the repeated footnote labels but it is also necessary because without it the code will not compile when you first define a new label, although it will be fine on all subsequent passes. On the first pass, when the labels are not defined, the MWE produces the following:

As @dalief points out, it is better to put the footnote inside \footnote{...} rather than redefining \@footnotemark as I have done above.

Answer 3

One solution could be the package fixfoot:

\documentclass[12pt]{memoir}
\usepackage[bmargin=20cm,lmargin=6cm,rmargin=6cm]{geometry}
\usepackage{fixfoot,xspace}
\usepackage[colorlinks]{hyperref}

\DeclareFixedFootnote{\foobar}{Run \texttt{pdflatex} two times.}
\DeclareFixedFootnote*{\foo}{A wonderful footnote!}
\DeclareFixedFootnote*{\baz}{A more wonderful footnote!}

\begin{document}

Compile this twice \foobar. One footnote,\foo and another.\baz 
The last footnote\baz is really nice. I like this footnote\baz 
more than footnote\foo, but check that the PDF is correctly 
generated.\foobar 

\end{document}

Answer 4

Since the repeated footnote references are needed after the footnote is created, the \label/\ref system with two LaTeX runs is not really needed. Instead the current value of the footnote counter can be saved in a macro and the macro with the number will become the argument for \footnotemark:

\documentclass{memoir}
\usepackage[height=30mm]{geometry}%

\begin{document}
  Lorem ipsum dolor%
  \footnote{See \emph{Appendix on dolors}}%
  \edef\thefndolors{\the\value{footnote}}
  sit amet, consectetur adipiscing elit%
  \footnote{See \emph{Appendix on elites}},%
  sed do eiusmod tempor incididunt ut labore et
  dolore\footnotemark[\thefndolors] magna aliqua. Ut enim ad minim
  veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex
  ea commodo consequat. Duis aute irure dolor\footnotemark[\thefndolors]
  in reprehenderit in voluptate velit esse cillum
  dolore\footnotemark[\thefndolors] eu fugiat nulla pariatur.
  Excepteur sint occaecat cupidatat non proident, sunt in culpa
  qui officia deserunt mollit anim id est laborum.
\end{document}