• [1] RFC 2046 - Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types (2015-03-22 13:14:46 +09:00 版) http://tools.ietf.org/html/rfc2046#section-5.2.3.2
• [2] RFC 2046 - Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types (2015-03-22 13:14:46 +09:00 版) http://tools.ietf.org/html/rfc2046#section-5.2.3.3
• [3] RFC 2046 - Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types (2015-03-22 13:14:46 +09:00 版) http://tools.ietf.org/html/rfc2046#section-5.2.3.4