\newcommand{\INVITE}{\textsf{INVITE}}
\newcommand{\BYE}{\textsf{BYE}}
\newcommand{\ACK}{\textsf{ACK}}
\newcommand{\INFO}{\textsf{INFO}}
\newcommand{\CANCEL}{\textsf{CANCEL}}
\newcommand{\OPTIONS}{\textsf{OPTIONS}}
\newcommand{\REGISTER}{\textsf{REGISTER}}
\newcommand{\MESSAGE}{\textsf{MESSAGE}}
\newcommand{\NOTIFY}{\textsf{NOTIFY}}
\newcommand{\SUBSCRIBE}{\textsf{SUBSCRIBE}}
\newcommand{\header}[1]{\textsf{#1}}
\newcommand{\host}[1]{\texttt{#1}}
\newcommand{\annotation}[1]{}

