\subsection{Idle Element}
\label{sec:idle}

The \xmlelement{idle} records the absolute time and date the
communication device was last used.  This provides an indication as to
how likely a user is to answer the device.  A device that has not been
used in a while may still be OPEN, but a watcher may choose to first
contact a device that is both OPEN and not marked as idle. 

The \xmlelement{idle} element can be empty if the presentity wants to
indicate that the device has not been used for a while, but does not
want to reveal the precise duration:

\begin{verbatim}
  <idle/>
\end{verbatim}

The \xmlelement{idle} {\SHOULD} be included in the presence document if
the idle time exceeds a user-setable threshold, with a {\RECOMMENDED}
default value of 10 minutes.  Configuration {\MUST} include the option
to omit the timestamp.
