[1] [whatwg] Html 5 video element's poster attribute ( (2010-12-10 00:28:05 +09:00 版)) http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2010-December/029397.html

[2] Web Applications 1.0 r7552 Try to be clearer about when the poster frame is shown. Better matches implementations (see first part of #10 in the bug). ( (2012-12-01 06:45:00 +09:00 版)) http://html5.org/tools/web-apps-tracker?from=7551&to=7552

[3] Web Applications 1.0 r7553 Match implementations better regarding intrinsic size of <video> with poster frame. This also changes the show poster flag to not change while script is running, so that you can't detect the change in intrinsic size if playback begins while script is executing. ( (2012-12-01 07:14:00 +09:00 版)) http://html5.org/tools/web-apps-tracker?from=7552&to=7553

[4] Web Applications 1.0 r8356 The spec wasn't clear about what to do if there's no poster frame. ( (2013-12-17 05:50:00 +09:00 版)) http://html5.org/tools/web-apps-tracker?from=8355&to=8356

[5] Integrate Fetch into HTML · whatwg/html@7c5555a (2015-09-18 19:11:31 +09:00 版) https://github.com/whatwg/html/commit/7c5555a16f2920c02244c10756bb2f1a11e87a22

[6] Fetch removes type in favor of just destination (annevk著, 2017-08-21 16:37:50 +09:00) https://github.com/whatwg/html/commit/5f59b7a73d450e244a573e5916deb1c2037c1366