[REFS[
- [1] [CITE@en[RFC 5438 - Instant Message Disposition Notification]] ([TIME[2014-09-07 06:11:14 +09:00]] 版) <http://tools.ietf.org/html/rfc5438#section-9>
- [2] [CITE@en[RFC 5438 - Instant Message Disposition Notification]] ([TIME[2014-09-07 06:11:14 +09:00]] 版) <http://tools.ietf.org/html/rfc5438#section-15.4>
]REFS]