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 table at https://developer.mozilla.org/en-US/docs/Web/CSS/attr#browser_compatibility uses the parameters as used in older versions of the spec. Things like <fallback> and <type-or-unit> are no longer present in the updated spec https://drafts.csswg.org/css-values-5/#attr-notation

What browsers does this problem apply to, if applicable?

No response

What did you expect to see?

Updated rows reflecting the new syntax at https://drafts.csswg.org/css-values-5/#attr-notation

Did you test this? If so, how?

N/A

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

https://drafts.csswg.org/css-values-5/#attr-notation
https://chromestatus.com/feature/4680129030651904

Do you have anything more you want to share?

I am working on a PR to update the page’s contents.

MDN URL

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

MDN metadata