:heading() no longer accepts odd, even or -n + 3 style notation

[bigandy]

MDN URL

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

What specific section or headline is this issue about?

No response

What information was incorrect, unhelpful, or incomplete?

https://drafts.csswg.org/selectors-5/#headings now only accepts integer list.

Since w3c/csswg-drafts#12599 (comment) and https://bugzilla.mozilla.org/show_bug.cgi?id=1984310

What did you expect to see?

:heading() accept only list of integers e.g. :heading(2,4,6) or :heading(1) or :heading(5,6)

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

csswg draft https://drafts.csswg.org/selectors-5/#headings
See wpt: web-platform-tests/wpt@be6456c

Since w3c/csswg-drafts#12599 (comment) and https://bugzilla.mozilla.org/show_bug.cgi?id=1984310

Do you have anything more you want to share?

No response

MDN metadata

Page report details

• Folder: en-us/web/css/_colon_heading_function
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/CSS/:heading_function
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/css/_colon_heading_function/index.md
• Last commit: 1a1fe4e
• Document last modified: 2025-08-20T08:57:58.000Z

[Josh-Cena]

@dletorey perhaps

[dletorey]

Yep I'm all over this. On my list