[1] [CITE@en[DOM 4 request]]
( ([[Richard Schwerdtfeger]] 著, [TIME[2013-03-10 06:05:10 +09:00]] 版))
<http://lists.w3.org/Archives/Public/www-dom/2013JanMar/0171.html>

[2] [CITE[''''''[''''''whatwg'''''']'''''' Document.activeElement should return the root element in non-HTML documents when no element has focus]]
( ([TIME[2014-02-03 19:43:13 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2014-February/041974.html>

[3] [CITE@en[Editorial: synchronize with the DOM Standard · whatwg/html@21c6ec7]]
([TIME[2016-03-20 18:16:07 +09:00]] 版)
<https://github.com/whatwg/html/commit/21c6ec77594eb89b836d4872222f5916910967fd>

[4] [CITE@en[Editorial: cleanup activeElement]]
([[annevk]]著, [TIME[2018-03-05 10:33:24 +09:00]])
<https://github.com/whatwg/html/commit/4823cf596e2ce499f3be67b486ffea261cbe4b29>

[5] [CITE@en[Editorial: cleanup activeElement by annevk · Pull Request #3513 · whatwg/html]]
([TIME[2018-03-06 17:39:12 +09:00]])
<https://github.com/whatwg/html/pull/3513>

[6] [CITE@en[Define DocumentOrShadowRoot's activeElement]]
([[rakina]]著, [TIME[2019-08-24 03:26:07 +09:00]])
<https://github.com/whatwg/html/commit/5b84d194c5ca0be9b738e0d46078131ca4a5f422>

[7] [CITE@en[Define DocumentOrShadowRoot.activeElement by rakina · Pull Request #4837 · whatwg/html]]
([TIME[2020-01-12 16:54:32 +09:00]])
<https://github.com/whatwg/html/pull/4837>

[8] [CITE@en[Shadow DOM and focus · Issue #1583 · whatwg/html]]
([TIME[2020-01-12 16:54:58 +09:00]])
<https://github.com/whatwg/html/issues/1583>