-for these functions are shown in Listing~\ref{lst:shares}. All of the
-operations are atomic in the sense that during reading no other tasks are
-executed.
+for these functions are shown in Listing~\ref{lst:shares}. By default, all
+shares are files containing a \gls{JSON} encoded version of the object and thus
+are persistent between restarts of the program. Library functions for shares
+residing in memory are available as well. The three main operations on shares
+are atomic in the sense that during reading no other tasks are executed.
+
+The basic type for \glspl{SDS} has three \todo{parametric
+lenses}\cite{domoszlai_parametric_2014}.