I'd like the section headings in running text to link to their "line" in the Table of Contents so as to get "two-way" navigation, eg: a user looks in the Table of Contents for a section title, jumps there, reads a couple of lines, clicks on the section title again and gets taken to the section's entry in the Table of Contents once more.
Any ideas? :)
(Somewhat related to this question)
Here's another approach, using the titlesec package and the \hypertarget, \hyperlink mechanism from hyperref. A little example showing the necessary settings for \chapter, \section, \subsection and their starred versions:
\documentclass{book} \usepackage[explicit]{titlesec} \usepackage{hyperref} \titleformat{\chapter}[display] {\normalfont\huge\bfseries}{\chaptertitlename\ {\fontfamily{cmr}\selectfont\thechapter}}{20pt}{\hyperlink{chap-\thechapter}{\Huge#1} \addtocontents{toc}{\protect\hypertarget{chap-\thechapter}{}}} \titleformat{name=\chapter,numberless} {\normalfont\huge\bfseries}{}{-20pt}{\Huge#1} \titleformat{\section} {\normalfont\Large\bfseries}{\thesection}{1em}{\hyperlink{sec-\thesection}{#1} \addtocontents{toc}{\protect\hypertarget{sec-\thesection}{}}} \titleformat{name=\section,numberless} {\normalfont\Large\bfseries}{}{0pt}{#1} \titleformat{\subsection} {\normalfont\large\bfseries}{\thesubsection}{1em}{\hyperlink{subsec-\thesubsection}{#1} \addtocontents{toc}{\protect\hypertarget{subsec-\thesubsection}{}}} \titleformat{name=\subsection,numberless} {\normalfont\large\bfseries}{\thesubsection}{0pt}{#1} \begin{document} \tableofcontents \chapter{Numbered test chapter one} \section{Test section one} \subsection{test subsection one one} \subsection{test subsection one two} \chapter*{Unnumbered test chapter one} \section*{Unnumbered test section} \subsection*{Unnumbered test subsection} \end{document} 
\renewcommand{\thechapter}{\texorpdfstring{\fontfamily{cmr}\selectfont\arabic{chapter}}{\arabic{chapter}}}, which basically gives me titling numbers in the sectionings (see tex.stackexchange.com/questions/31942/…). Should I mark your answer as accepted (it does work)? do you have any ideas how to make both things "compatible"? \titleformat, so there's no need to use the problematic \renewcommand\thechapter{...}. \hyperlink{subsec-\thechapter-\thesection-\thesubsection}{#1} and hypertarget{subsec-\thechapter-\thesection-\thesubsection}{} * chapters / sections / subsections / etc. The MWE you propose fails with a duplicate warning. This solution sets up \hypertargets in the toc by renewing the \contentsline command. It links back to the toc by setting the section headings as \hyperlinks using the titlesec package. Note that each of the new \hypertarget start with the word 'toc'
You can easily copy this approach for chapters etc.
\documentclass{article} \usepackage{lipsum} % sample text \usepackage[explicit]{titlesec} % to change headings \usepackage{hyperref} % renew \contentsline for toc to include hypertarget \let\oldcontentsline\contentsline% \renewcommand\contentsline[4]{% \hypertarget{toc#4}{}% \oldcontentsline{#1}{#2}{#3}{#4}} % renew \section to link to the toc \titleformat{\section} {\normalfont\Large\bf} {{\thesection} \hyperlink{tocsection.\thesection}{#1}} {1pc} {} % renew \subsection to link to the toc \titleformat{\subsection} {\normalfont\bf} {{\thesection} \hyperlink{tocsubsection.\thesubsection}{#1}} {1pc} {} \begin{document} \tableofcontents \clearpage \section{First section} \lipsum[1] \subsection{my sub section} \lipsum[1] \section{Second section} \lipsum[2] \clearpage \section{Third section} \lipsum[3] \end{document} Explanation
Note that if you look at the .toc file for the above example you'll see the following entries
\contentsline {section}{\numberline {1}First section}{2}{section.1} \contentsline {subsection}{\numberline {1.1}my sub section}{2}{subsection.1.1} \contentsline {section}{\numberline {2}Second section}{2}{section.2} \contentsline {section}{\numberline {3}Third section}{3}{section.3} The \contentsline takes four arguments, the fourth of which will uniquely identify each entry. I used this unique entry combined with the string 'toc' as the \hypertarget{toc#4}{}; it would not work without the additional string 'toc' (or something similar), as it would result in a duplicated identifier which would be ignored.
I wrote a very simple example of myself.
\documentclass{article} \usepackage{lipsum} \usepackage{hyperref} \let\oldsection\section \renewcommand\section[1]{% \addtocontents{toc}{\protect\hypertarget{#1}{}} \oldsection{\texorpdfstring{\protect\hyperlink{#1}{#1}}{#1}} } %% \let\oldsubsection\subsection \renewcommand\subsection[1]{% \addtocontents{toc}{\protect\hypertarget{#1}{}} \oldsubsection{\texorpdfstring{\protect\hyperlink{#1}{#1}}{#1}} } %% \begin{document} { \let\section\oldsection \pdfbookmark{Contents}{Contents} \vspace*{.5cm} \tableofcontents } \clearpage \section{First section} \lipsum[1] \subsection{my sub section} \lipsum[1] \section{Second section} \lipsum[2] \clearpage \section{Third section} \lipsum[3] \end{document} 