[4] HTTP 要求 >>2 や SSDP >>3 で使います。
[1] draft-cohen-gena-client-00 - General Event Notification Architecture Base: Client to Arbiter ( (2014-06-15 05:42:57 +09:00 版)) <http://tools.ietf.org/html/draft-cohen-gena-client-00#section-8.2>