* 歴史

** VPIM (v1)

[REFS[
- [1] [CITE@en[RFC 1911 - Voice Profile for Internet Mail]]
( ([TIME[2014-11-03 00:29:14 +09:00]] 版))
<http://tools.ietf.org/html/rfc1911>
]REFS]

** VPIMv2

[REFS[
- [2] [CITE@en[RFC 2421 - Voice Profile for Internet Mail - version 2]] ([TIME[2014-08-04 01:19:09 +09:00]] 版) <http://tools.ietf.org/html/rfc2421>
- [3] [CITE@en[RFC 3801 - Voice Profile for Internet Mail - version 2 (VPIMv2)]] ([TIME[2014-09-07 15:46:36 +09:00]] 版) <http://tools.ietf.org/html/rfc3801>
]REFS]

[4] [CITE@en[RFC 2423 - VPIM Voice Message MIME Sub-type Registration]], [TIME[2021-01-24T15:36:42.000Z]], [TIME[2021-03-26T05:54:34.504Z]] <https://tools.ietf.org/html/rfc2423>



[5] [CITE@en[rfc3804]], [TIME[2021-06-11T05:33:25.000Z]] <https://datatracker.ietf.org/doc/html/rfc3804>