CSS Nesting 1: the two forms of “Example nesting Scoping” are called equivalent but set different properties

In example #example-81212ace of §3.3 the nested form sets border on :scope, while the form given as “equivalent to” sets only border-block-end. The scoping examples in §3.2 use border-block-end in both forms, so border here looks like a typo.

Consequence

With no other styles, the nested form draws four borders on .card and the “equivalent” form draws one.

Proposed correction

Use border-block-end: 1px solid white; in the nested form as well.

Issued by

World Wide Web Consortium (W3C) — CSS Working Group

Act

CSS Nesting Module Level 1 (Editor's Draft, 8 October 2026)

Place

§3.3, example #example-81212ace

Record

Discrepancy

Class

Text of the act

Where it arose

The text of the act

Arxo's conclusion

Confirmed

Official text

Unchanged at last check

Last checked

2026-10-31

Evidence

Reproduced by execution. Quotations are verbatim from the official material; translations are ours and marked.

@scope (&) { :scope { border: 1px solid white; } }

@scope (.card) { :scope { border-block-end: 1px solid white; } }

How to check it without Arxo's tools

1. Open CSS Nesting Module Level 1, Editor's Draft of 8 October 2026 (W3C CSS Working Group) and find §3.3 Nesting Other At-Rules, example #example-81212ace. Compare the text with the quotation above. A copy is kept in this register: 82a526ba3c93c8ff-ed-css-nesting-1.html (SHA-256 82a526ba3c93c8ff23b8b3d22296e320a66884bdc1f12f55b2533e2d3b2d5555, copy of the official file).
2. The finding holds if the quoted passages read as shown and the comparison gives the result stated at the top of this page. If it does not, write to us with the record ID.

How this finding was made

AI agents read the specifications and compared their sections; the example was also run through executable rules of both readings. An AI coordinator checked the place against the full Editor's Draft and the Working Group's issue tracker, and two further AI models checked the report before filing.

Responsible institutions

• W3C CSS Working Group — maintains the specification

Reported to

Responses

No response recorded.

History

1. 2026-10-31Confirmed by Arxo
2. 2026-10-31Entered in the register
3. 2026-10-31Reported to W3C CSS Working Group (public issue tracker)

Cite this record

Arxo Law, Arxo Findings Register, ARXO-2026-0338, https://arxo.io/findings/ARXO-2026-0338/ (status as of 2026-10-31). Data: ARXO-2026-0338.json.