Note: This answer is now outdated; see herehere.
Selective numbering is not supported at the moment (even in Org-mode master). However you can choose to not number headings beyond a certain depth by specifying something like this:
#+OPTIONS: H:3 num:2 * Introduction * Heading ** Something 1 *** Something 2 * Heading ** Something 1 *** Something 2 * References The above will export up to 3 levels of headlines but will number only up to level 2.
\section{Introduction} \label{sec-1} \section{Heading} \label{sec-2} \subsection{Something 1} \label{sec-2-1} \subsubsection*{Something 2} \label{sec-2-1-1} \section{Heading} \label{sec-3} \subsection{Something 1} \label{sec-3-1} \subsubsection*{Something 2} \label{sec-3-1-1} \section{References} \label{sec-4} PS: I don't see how this is more appropriate in tex rather than stackoverflow.