[1] List of HTTP status codes - Wikipedia, the free encyclopedia ( (2012-02-16 13:47:30 +09:00 版)) <http://en.wikipedia.org/wiki/List_of_HTTP_status_codes>

[2] List of HTTP status codes - Wikipedia, the free encyclopedia ( (2013-10-01 11:44:11 +09:00 版)) <http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#449>