# Using section sign (§) for cross-references to sections

In some papers and books you see that author uses §1.3 instead of section 1.3. How § sign can be added before section (or part, chapter, ...) number automatically? Please mention any useful tip about this style.

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You could use the cleveref package and redefine \crefname{section}:

\documentclass{article}

\usepackage[utf8]{inputenc}

\usepackage{cleveref}
\crefname{section}{§}{§§}
\Crefname{section}{§}{§§}

\begin{document}

\section{foo}\label{sec:foo}

Some text.

\section{bar}

As explained in \cref{sec:foo}~\dots

\end{document}


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+1 you can avoid inputenc by using \S –  cmhughes Jun 15 '12 at 3:59
@lockstep Little late to the party here, but can the space after § be removed? –  jstephenson Feb 22 '13 at 17:12
@jstephenson Use \crefformat{section}{§#2#1#3}. –  lockstep Feb 24 '13 at 11:42

hyperref provides \autoref{<label>} that checks the counter used in the reference and sets a label with a prepended \<counter>autorefname. Here's a small example:

\documentclass{article}
\usepackage{hyperref}% http://ctan.org/pkg/hyperref
\renewcommand{\sectionautorefname}{\S}
\begin{document}
\section{A section}
See~\autoref{another-section}.
\section{Another section}\label{another-section}
\end{document}​

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What I have done is the past is also redefined \subsectionautorefname and \subsubsectionautorefname to be the same as \sectionautorefname so that you can get "See § 2.1" or "See § 3.2.1". If one also uses autopageref, one can also redefine \pageautorefname to "p." to get "See § 3.2 on p. 4" –  ArTourter Jun 14 '12 at 18:39

Often forgotten is the macro \p@<counter>. If LaTeX generates a reference value, this is not just \the<counter> but \p@<counter>\the<counter>. If a new counter is defined, \p@<counter> is defined empty. But it can be redefined to add a prefix, for example. Thus there is no need for additional packages.

\documentclass{article}

\makeatletter
\renewcommand*{\p@section}{\S\,}
\renewcommand*{\p@subsection}{\S\,}
\makeatother

\begin{document}

\section{Hello World}
\label{sec:hello}
\subsection{Subsection A}
\subsection{Subsection B}
\subsection{Subsection C}
\label{sec:C}

See \ref{sec:C} inside \ref{sec:hello}.
\end{document}

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Should that be \renewcommand*{\p@subsection}{\S\S\,} instead? –  J. C. Salomon Aug 7 '12 at 5:03
The double form of the section sign is used, if it refers to the plural form. –  Heiko Oberdiek Aug 7 '12 at 6:43