[1] RFC 5612 - Enterprise Number for Documentation Use (2009-12-21 03:05:41 +09:00 版) <http://tools.ietf.org/html/rfc5612>

[2] RFC 5585 - DomainKeys Identified Mail (DKIM) Service Overview (2009-10-20 11:58:17 +09:00 版) <http://tools.ietf.org/html/rfc5585>