From #4816 (review) comment by @domenic

Could you say a bit more about the comparison with https://drafts.csswg.org/css-lists/#ua-stylesheet ? Specific things I wonder about:

• [...]
• marker-side: match-parent; on ol, ul
• text-align: match-parent; on li

(marker-side should probably apply to menu as well.)

marker-side is defined here: https://drafts.csswg.org/css-lists/#marker-side
text-align: match-parent is defined here: https://drafts.csswg.org/css-text/#valdef-text-align-match-parent

None of Gecko, WebKit, Chromium support the marker-side property, AFAICT.

Gecko has text-align: match-parent; on li: https://searchfox.org/mozilla-central/rev/2b99ea2e97eef00a8a1c7e24e5fe51ab5304bc42/layout/style/res/html.css#603 (Bug 645642)

WebKit and Chromium use text-align: -webkit-match-parent;:
https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/renderer/core/html/resources/html.css;l=357;drc=78c94894dfa3edca8d26b643f592751575edaf5a
https://github.com/WebKit/WebKit/blob/c87fa091ba26dabd4367c97c99bc5a9b448a97f1/Source/WebCore/css/html.css#L302

cc @whatwg/css