[REFS[
- [2] [CITE@en[RFC 3959 - The Early Session Disposition Type for the Session Initiation Protocol (SIP)]] ([TIME[2014-09-21 08:16:00 +09:00]] 版) <http://tools.ietf.org/html/rfc3959>
- [3] [CITE[RFC Errata Report]] ([TIME[2014-11-03 03:57:14 +09:00]] 版) <http://www.rfc-editor.org/errata_search.php?rfc=3959>
- [1] [CITE@en[RFC 5621 - Message Body Handling in the Session Initiation Protocol (SIP)]] ([TIME[2014-09-14 07:55:49 +09:00]] 版) <http://tools.ietf.org/html/rfc5621#section-6.2>
]REFS]