\section{Serialisations}
\label{sect:serialisations}

This section presents various attempts of serialisation using different strategies. 

Subsection 1 is using VOTable  GROUPs  for separating axes in the serialisation and is using utypes from different models  on GROUPS and FIELDS. It has been written by Jiri Nadvornik.
Subsection 2 "Full utype serialisation" subsection has been written by F.Bonnarel. 
Subsection 3 is using the full VO-DML mapping serialisation and has been written by Mark Cresitello.
Subsection 3 is a proposal for a "Lighter"  VO-DML mapping serialisation and  has been written by Laurent Michel.