[css-2024] Add features to Safe to Release pre-CR Exceptions

[SebastianZ]

Here's a (very hand-wavy) list of features I believe could be added to the "Safe to Release pre-CR Exceptions" section of CSS 2024:

• All from CSS Animations 2
• font-tech() and font-format() from CSS Conditional 5
• linear() from CSS Easing 2 (requires to publish a FPWD)
• env() from CSS Environment Variables 1 (still some open issues but interoperably implemented, requires to publish a FPWD)
• All from CSS Highlight API
• All from CSS Images 4
• text-box-trim and text-box-edge from CSS Inline Layout 3
• All from CSS Overflow 3
• All from CSS Paged Media 3
• Typographic pseudo-elements, ::before, ::after from CSS Pseudo-Elements 4 (basically all from CSS 2 with double-colon syntax plus ::prefix and ::postfix)
• :is(), :where(), :has(), and selector lists in :not() from Selectors 4 (Selectors 4 is also suggested to be added to "Rough Interoperability".)
• text-decoration-thickness, text-underline-offset properties and from-font value for text-underline-position from CSS Text Decorations 4
• transition-behavior property, @starting-style rule and CSSStartingStyleRule interface of CSS Transitions 2
• accent-color property,auto value for outline-color property, and <url-set> value for the cursor property from CSS UI 4
• Several of the interfaces defined in CSSOM 1 (which I believe should be cut now regarding its feature set and a CSSOM 2 spec. started for new features, see #10686)

For this list I went through all the specs and checked what seems fairly stable to me based on issues within the spec. and on GitHub and/or is already widely implemented in browsers. For some I checked the WPT coverage, though not all. I may go through them and provide some more detailed info. And there are surely some Interop 2023 and 2024 features I didn't list here yet, which might be added.

Everyone is encouraged to edit this list or suggest additions, changes, or removals! And let me know if it makes sense to split it into separate issues to discuss them individually!

Sebastian

[svgeesus]

• linear() from CSS Easing 2 (requires to publish a FPWD)

Yes we absolutely need a FPWD :) also it would be good if the spec had WPT annoutations to show how well it is tested

[svgeesus]

In general, if the proposal for pre-CR exceptions is "all from spec foo" then it kind of implies that foo should move to CR.

[SebastianZ]

In general, if the proposal for pre-CR exceptions is "all from spec foo" then it kind of implies that foo should move to CR.

Agree, though some of them have a lot of open issues (in-spec and/or on GitHub), but all of their features are widely implemented. Not sure how to handle those. I'll try to dig up some numbers, so we can get a better picture of their actual state, though that'll take a bit.

Sebastian