\documentclass[
9pt, % 8-20pt possible
% twocolumn, % switch, use twocolumn layout
techreport, % select between ``techreport'', ``report'', ``article'', ``commun'', ``persp'' and ``review''
% lineno, % switch, adds line numbering
% tocfig, % switch, use a TOC figure at the top (place in ./figs)
% SI, % switch to Supplemental Information format, not compatible with twocolumn
affiltop, % switch, put affiliations under authors (instead of footnote)
% nofootprint, % do not add "Preprint" in footer
% nofootdate, % do not add date in footer
% debug, % switch, add debugging boxes
% draft, % for quick compilations (no figures, references etc)
]{art}
\input{metadata.tex}
\input{macros.tex}
\begin{document}
\maketitle
% \iftoggle{SI}{}{\ifdef{\pubSI}{\footnotetext{\pubSI}}{}}
\tableofcontents
\section{Introduction}
\section{Concluding remarks}
\section{Acknowledgements}
\nocite{*}
\bibliography{ref.bib}
\appendix
\section{Some extra stuff}
\end{document}