\subsection{Proxy Behavior}
\label{sec:proxy}

SIP proxies may ignore, inspect, insert and modify the
\header{Resource-Priority} header field.  SIP proxies {\MAY} downgrade
the \header{Resource-Priority} of or reject unauthenticated requests. 
Details are a matter of local policy.

\motivation{This behavior is similar to that for any header field, as a
UA can decide to reject a request for the presence, absence or value of
any information in the request.}

If a stateful proxy has authorized a particular resource priority level
and if it offers differentiated treatement to responses containing
resource priority levels, the proxy {\SHOULD} ignore any higher value
contained in responses, to avoid that colluding user agents artificially
raise the priority level.

\motivation{It is unlikely that the resource priority value in responses
will have any influence on response handling.}

A SIP proxy {\MAY} use the \header{Resource-Priority} indication in its
routing decisions, e.g., to find a next hop that is reserved for a
particular resource priority. 

There do not appear to be any special considerations when forking
requests containing a resource priority indication.

Otherwise, the proxy behavior is the same as for user agent servers
(Section~\ref{sec:uas}).
