\section{Changes in Version -08}

Since version -07, the following changes have been made. 

\begin{itemize}
\item Allow \header{maddr} to contain host names, not just IP multicast
addresses.  This is useful to allow multicast addresses of the form {\tt
mcast.net} as well as for redirecting requests to a different server
without changing the \header{Request-URI}. Added note to that effect to
description of 302.

\item Added references to symbolic name {\tt sip.mcast.net}.

\item {\REGISTER} requests without \header{Location} are quite useful to
obtain the current lists of registrations.  

\item Added ``comment'' to \header{Location} header to allow responses
like {\tt Location: alice@example.com (Alice)}. The more natural
solution conforming to the format of \header{From} and \header{To} is,
unfortunately, not backward compatible with HTTP.

\item Allow \header{Content-Length} to be optional, in line with HTTP.
This does not seem to complicate matters, but makes the processing of
cgi-style output much easier, since the server doesn't have to store the
output to compute the \header{Content-Length}.

\item Fixed table 4:  \header{CSeq} is now mandatory for all requests.

\item Since \header{To}, \header{From}, and \header{Call-ID} are used as
a call-leg identifier even in proxies, encryption of \header{From} needs
to be disallowed.

\item \header{Organization} is now a general header; no reason not to
allow the callee to insert its organization.

\item \header{Record-Route} BNF changed to SIP-URL.

\item \header{Via} operation clarified.

\item Additional BNF added to appendix.

\item Tag usage descriptions made consistent.

\end{itemize}
