Formal syntax doesn't use css images level 4 spec

[MarcellPerger1]

MDN URL

https://developer.mozilla.org/en-US/docs/Web/CSS/gradient/radial-gradient

What specific section or headline is this issue about?

Formal syntax section

What information was incorrect, unhelpful, or incomplete?

The formal syntax here is outdated, it's missing the <color-interpolation-method> stuff (the content was updated to include this in #30027) but the formal syntax still needs to be updated (probably not in this repo but in mdn/data)

What did you expect to see?

Up-to-date formal syntax

Do you have any supporting links, references, or citations?

https://www.w3.org/TR/css-images-4/#funcdef-radial-gradient

Do you have anything more you want to share?

This also happens on the other gradient pages, possibly also in some other places too.

MDN metadata

Page report details

• Folder: en-us/web/css/gradient/radial-gradient
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/CSS/gradient/radial-gradient
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/css/gradient/radial-gradient/index.md
• Last commit: 0cc9980
• Document last modified: 2025-07-14T14:43:58.000Z

[OnkarRuikar]

The formal syntax data comes from w3/webref repository. We show formal syntax from only the "current specification" and not the latest specs. Because it is guaranteed that all the features from the current spec are implemented in major browsers.

If we show the latest spec syntax, then there would be some unimplemented features in it. People will start raising issues saying not everything in the syntax is documented on the page. It is policy of MDN to not document unimplemented features.

The formal syntax will be updated when the CSS Images Module Level 4 spec becomes current.

[MarcellPerger1]

Doesn't the data use come from https://github.com/mdn/data/blob/main/css/syntaxes.json (I know that data then comes from the w3 repository). So why can't we just update that json file in mdn/data to reflect what browsers actually support (you can see in the MDN url above that it is supported by all browsers) and this way it will actually be in line with the rest of the documentation on the same page (I was really confused when the formal syntax section had no mention of the color interpolation method).

I would personally expect the documentation to be at least consistent with itself.
So if the policy is not documenting the already-implemented parts of CSS-images 4, the color interpolation stuff shouldn't be there.
If the policy is documenting implemented features, the formal specification should also follow this and should contain the color interpolation stuff. People can (and should) just check the browser compatibility table.

[MarcellPerger1]

Doesn't the data use come from https://github.com/mdn/data/blob/main/css/syntaxes.json (I know that data then comes from the w3 repository). So why can't we just update that json file in mdn/data to reflect what browsers actually support (you can see in the MDN url above that it is supported by all browsers) and this way it will actually be in line with the rest of the documentation on the same page (I was really confused when the formal syntax section had no mention of the color interpolation method).

I would personally expect the documentation to be at least consistent with itself.
So if the policy is not documenting the already-implemented parts of CSS-images 4, the color interpolation stuff shouldn't be there.
If the policy is documenting implemented features, the formal specification should also follow this and should contain the color interpolation stuff. People can (and should) just check the browser compatibility table.

[OnkarRuikar]

For more context, refer https://github.com/orgs/mdn/discussions/442