[5] [[WinIE]] が実装していました。

[1] [CITE@en[Make <body topmargin> win over <iframe marginheight> (#2489)]]
([[zcorpan]]著, [TIME[2017-04-18 06:41:29 +09:00]])
<https://github.com/whatwg/html/commit/3fc830124986d8fb0aa53cd2d2f2fea12a926e5d>

[2] [CITE@en[Editorial: fix a typo in Obsolete features]]
([[takenspc]]著, [TIME[2018-03-31 12:40:34 +09:00]])
<https://github.com/whatwg/html/commit/c3c7d2cb656bea5b8916097e13079b754e329f7c>

[3] [CITE@en[A typo in 15.2 Non-conforming features · Issue #3602 · whatwg/html]]
([TIME[2018-04-04 15:44:21 +09:00]])
<https://github.com/whatwg/html/issues/3602>

[4] [CITE@en[Editorial: fix a typo in Obsolete features by takenspc · Pull Request #3603 · whatwg/html]]
([TIME[2018-04-04 15:44:27 +09:00]])
<https://github.com/whatwg/html/pull/3603>