[1] [CITE[offsetParentプロパティ]] ([TIME[1999-11-21 05:57:32 +09:00]] 版) <http://homepage1.nifty.com/kodayan/dhtm/css/position20.htm>

[2] [CITE@en['''['''cssom-view''']''' Update offsetParent spec for Shadow DOM]]
([[TakayoshiKochi]]著, [TIME[2016-08-11 17:48:51 +09:00]])
<https://github.com/w3c/csswg-drafts/commit/9386def5f11fe47ffbaa8cda2ddd9c204a6a07cf>