\subsection{Type of Place Element}
\label{sec:placetype}

The \xmlelement{placetype} element describes the type of place the
presentity is currently at. This offers the watcher an indication what
kind of communication is likely to be appropriate. We define an initial
set of values below:

\begin{description}
\item[home:] The presentity is in a private or residential setting, not
necessarily the personal residence of the presentity, e.g., including
hotel or a friend's home.

\item[office:] The presentity is in a business setting, such as an office.

\item[public:] The presentity is in a public area such as a shopping
mall, street, park, public building, train station, airport or in public
conveyance such as a bus, train, plane or ship. Alternatively, the more
detailed indications below may be provided.

\item[street:] Walking in a street.

\item[public-transport:] Any form of public transport, including
aircraft, bus, train or ship.

\item[aircraft:] The presentity is in a plane, helicopter or balloon.

\item[ship:] Water vessel, boat.

\item[bus:] Public bus.

\item[train:] The presentity is traveling in a train.

\item[airport:] Airport, heliport or similar location.

\item[station:] Bus or train station.

\item[mall:] Shopping mall or shopping area.

\item[outdoors:] General outdoors area, such as a park or city streets.

\end{description}

This list can be augmented by free-text values or additional
IANA-registered values (Section~\ref{sec:iana}).

The \element{placetype} element {\MAY} be qualified with the 'from' and
'until' attributes to describe the time when the element assumed this
value and the time until which is element is expected to be valid.  The
'from' time {\MUST} be in the past, the 'until' time in the future
relative to the publication of the presence information.

\motivation{The \element{placetype} element can be used by logic
executing on the watcher or by a composer to filter, sort and label
tuples.  For example, a composer may have rules that limit the
publication of ``home'' tuples to a subset of the watchers.}
