list-style-item incorrectly reports support for many keys

[jamesnw]

What type of issue is this?

Incorrect support data (example: BrowserX says "86" but support was added in "40")

What information was incorrect, unhelpful, or incomplete?

The list-style-item supports predefined list style types, custom strings, and identifiers for custom counters. The collector is checking for support using CSS.supports('list-style-item', 'value'), and because of the breadth of values, this will return true for anything passed as the value. This means that the some of the changes introduced by #4148 are not accurate.

What browsers does this problem apply to, if applicable?

No response

What did you expect to see?

The following are NOT in the spec as predefined list style types. These should not be marked as standard-track, likely should be marked as deprecated, and the support should be reevaluated.

• afar
• amharic
• amharic-abegede
• asterisks
• binary
• ethiopic
• ethiopic-abegede
• ethiopic-abegede-am-et
• ethiopic-abegede-gez
• ethiopic-abegede-ti-er
• ethiopic-abegede-ti-et
• ethiopic-halehame
• ethiopic-halehame-aa-er
• ethiopic-halehame-aa-et
• ethiopic-halehame-am
• ethiopic-halehame-am-et
• ethiopic-halehame-gez
• ethiopic-halehame-om-et
• ethiopic-halehame-sid-et
• ethiopic-halehame-so-et
• ethiopic-halehame-ti-er
• ethiopic-halehame-ti-et
• ethiopic-halehame-tig
• footnotes
• hangul
• hangul-consonant
• lower-hexadecimal
• lower-norwegian
• octal
• oromo
• sidama
• somali
• tigre
• tigrinya-er
• tigrinya-er-abegede
• tigrinya-et
• tigrinya-et-abegede
• upper-greek
• upper-hexadecimal
• upper-norwegian
• urdu

Did you test this? If so, how?

Tested CSS.supports in Safari, Chrome, Firefox.

Also tested individual values, and some are actually supported, despite not being in the spec.
https://codepen.io/jamessw/pen/mdNJVVN

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

https://drafts.csswg.org/css-lists-3/#text-markers
https://drafts.csswg.org/css-counter-styles-3/#predefined-counters

Do you have anything more you want to share?

Surfaced in web-platform-dx/web-features#1764

MDN URL

No response

MDN metadata

No response

[jamesnw]

Relevant source code which may be useful in determining support-

1. Chromium lists several as "non-standard counter styles that we've been supporting"- https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/css/ua_counter_style_map.cc;l=429?q=ethiopic-halehame&sq=
2. Firefox- https://github.com/mozilla/gecko-dev/blob/57e9b5f68c11ae005ba067192375b0dfdcec50ca/layout/style/res/counterstyles.css#L320