@misc{rfc3680,
    series =    {Request for Comments},
    number =    3680,
    howpublished =  {RFC 3680},
    publisher = {RFC Editor},
    doi =       {10.17487/RFC3680},
    url =       {https://www.rfc-editor.org/info/rfc3680},
    author =    {Jonathan Rosenberg},
    title =     {{A Session Initiation Protocol (SIP) Event Package for Registrations}},
    pagetotal = 26,
    year =      2004,
    month =     mar,
    abstract =  {This document defines a Session Initiation Protocol (SIP) event package for registrations. Through its REGISTER method, SIP allows a user agent to create, modify, and delete registrations. Registrations can also be altered by administrators in order to enforce policy. As a result, these registrations represent a piece of state in the network that can change dynamically. There are many cases where a user agent would like to be notified of changes in this state. This event package defines a mechanism by which those user agents can request and obtain such notifications. {[}STANDARDS-TRACK{]}},
}