How to highlight citations in a revised manuscript

Question

I am submitting a revised manuscript to a journal (Medical Physics), and the journal requires that changes that are made in the revised manuscript should be highlighted. I've been attempting to use the soul package with the \hl command, but it seems that there is a known bug where you can't highlight citations. (You get a compilation error.) I have found some workarounds, but they don't seem to work for multiple citations like this: \cite{rockafellar1997convex,rudin1992nonlinear}. Also, the workarounds seem ugly, and I don't want to submit a latex file contaminated with ugly hacks for highlighting that the editors will not understand.

How do people handle this? It must be a common issue.

Should I just highlight the pdf using Adobe Acrobat and then submit a highlighted version of the pdf along with my latex file? I'm not sure that the journal will accept that -- they may want to receive just one manuscript that has the highlighting built in, rather than a manuscript and a separate pdf with highlighting.

Here is a minimal working example:

\documentclass[aapm,graphicx,preprint,showkeys]{revtex4-1} 
\usepackage{amsmath,amssymb,enumitem,mathtools}
\usepackage{xcolor}
\usepackage{soul}

\begin{document}

\hl{This text is highlighted}.

Here's a citation \cite{rockafellar1997convex,rudin1992nonlinear}.

%\hl{ Highlighting a citation causes a compilation error \cite{rockafellar1997convex,rudin1992nonlinear}. }

\begin{thebibliography}{10}

\bibitem{rockafellar1997convex}
R.T. Rockafellar.
\newblock {\em Convex analysis}.
\newblock Number~28. Princeton university press, 1997.

\bibitem{rudin1992nonlinear}
L.~Rudin, S.~Osher, and E.~Fatemi.
\newblock Nonlinear total variation based noise removal algorithms.
\newblock {\em Physica D: Nonlinear Phenomena}, 60(1):259--268, 1992.

\end{thebibliography}

\end{document}

Answer 1

I don't know your other reasons for using the soul package, but doesn't the xcolor package suffice? Moreover, if I read the author's instructions correctly, you can also choose to use just a different text color.

Here are some possibilities for highlighting. Changing the background color usually entails some limitations, like boxes that don't wrap or restrictions on what can be put inside the highlighted area; but citations work with all approaches.

\documentclass[aapm,graphicx,preprint,showkeys]{revtex4-1} 
\usepackage{amsmath,amssymb,enumitem,mathtools}
\usepackage{xcolor}
\newcommand\hl[1]{\colorbox{yellow}{\textcolor{red}{#1}}}
\newcommand\hlbreakable[1]{\textcolor{red}{#1}}
\usepackage[most]{tcolorbox}
\newtcolorbox{highlighted}{colback=yellow,coltext=red,breakable}
\usepackage{lipsum}
\begin{document}

\hl{This text is highlighted.}

\hl{Highlighting a citation causes no compilation error \cite{rockafellar1997convex,rudin1992nonlinear}.}

\hlbreakable{Highlighting a citation causes no compilation error \cite{rockafellar1997convex,rudin1992nonlinear}.
\lipsum}

\begin{highlighted}
Highlighting a citation causes no compilation error \cite{rockafellar1997convex,rudin1992nonlinear}.
\lipsum
\end{highlighted}

\begin{thebibliography}{10}
\bibitem{rockafellar1997convex}
  R.T. Rockafellar.
  \newblock {\em Convex analysis}.
  \newblock Number~28. Princeton university press, 1997.
\bibitem{rudin1992nonlinear}
  L.~Rudin, S.~Osher, and E.~Fatemi.
  \newblock Nonlinear total variation based noise removal algorithms.
  \newblock {\em Physica D: Nonlinear Phenomena}, 60(1):259--268, 1992.
\end{thebibliography}
\end{document}

Edit: It may be more convenient to define the \hlbreakable command as an environment, since \begin-\end pairs are easier to trace than pairs of braces.

\newenvironment{hlbreakable}%
  {\color{red}}%
  {}
...
\begin{hlbreakable}
Highlighting a citation causes no compilation error \cite{rockafellar1997convex,rudin1992nonlinear}.
\lipsum
\end{hlbreakable}

Answer 2

You only need the "soul" and "color" packages for this to work. Inside the "\hl{...}" command, instead of just putting in "\cite{...}", type "\mbox{\cite{...}}". This should do it.

Without the color/xcolor it will only underline instead of adding the yellow background.

Answer 3

A pragmatic solution would be to use some other, less intrusive implementation of highlighting. In the following, I define the \hl command to just switch the text color to red (slightly toned for better readability):

\documentclass{article} 
\usepackage{amsmath,amssymb,enumitem,mathtools}
\usepackage{xcolor}

\newcommand\hl[1]{%
  \bgroup
  \hskip0pt\color{red!80!black}%
  #1%
  \egroup
}

\begin{document}

\hl{This text is highlighted}.

Here's a citation \cite{rockafellar1997convex,rudin1992nonlinear}.

\hl{ Highlighting a citation does no longer cause a compilation error and even  works across line breaks \cite{rockafellar1997convex,rudin1992nonlinear}.}

\begin{thebibliography}{10}

\bibitem{rockafellar1997convex}
R.T. Rockafellar.
\newblock {\em Convex analysis}.
\newblock Number~28. Princeton university press, 1997.

\bibitem{rudin1992nonlinear}
L.~Rudin, S.~Osher, and E.~Fatemi.
\newblock Nonlinear total variation based noise removal algorithms.
\newblock {\em Physica D: Nonlinear Phenomena}, 60(1):259--268, 1992.

\end{thebibliography}

\end{document}

This simple approach looks less fancy, but has a lot of advantages: It works over most content (headings, tables, formulas, ...), is more printer-friendly and – taking the viewpoint of the reviewer – a lot more friendly for the reviewer's eye.