\documentclass[11pt]{article} 
\usepackage[latin1]{inputenc} 
\usepackage[T1]{fontenc} 
\usepackage{textcomp}
\usepackage{fullpage} 
\usepackage{url} 
\usepackage{ocamldoc}
\begin{document}
\tableofcontents
\section{Module {\tt{Latex\_ref}} : Latex-only test}
\label{Latex-underscoreref}\index{Latex-underscoreref@\verb`Latex_ref`}




\ocamldocvspace{0.5cm}



\subsection*{Title }
\label{lbl}


    Check that this text[\ref{lbl}] is present in the generated latex
    with a reference to [\ref{lbl}].

\end{document}