CSS property appearance: duplicate base tag?

[bbannon]

MDN URL

https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties/appearance

What specific section or headline is this issue about?

formal syntax

What information was incorrect, unhelpful, or incomplete?

Is 'base' supposed to be listed twice?

What did you expect to see?

'base' just once

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

No response

Do you have anything more you want to share?

I wish these pages had a working example of '@Property' that could be copied.

MDN metadata

Page report details

• Folder: en-us/web/css/reference/properties/appearance
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties/appearance
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/css/reference/properties/appearance/index.md
• Last commit: bcbb4bd
• Document last modified: 2026-04-20T01:47:07.000Z

[hamishwillee]

@bbannon I can't see it listed twice in https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties/appearance

Can you please screen shot and highlight the problematic part - or create a PR to fix it and cross link.

[bbannon]

3rd and 7th item in list Formal syntax <https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties/appearance#formal_syntax> appearance = none | <https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Values_and_units/Value_definition_syntax#single_bar> auto | <https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Values_and_units/Value_definition_syntax#single_bar> base | <https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Values_and_units/Value_definition_syntax#single_bar> < base-select | <https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Values_and_units/Value_definition_syntax#single_bar> <compat-auto> | <https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Values_and_units/Value_definition_syntax#single_bar> <compat-special> | <https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Values_and_units/Value_definition_syntax#single_bar> base <

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On Thu, Aug 20, 2026 at 6:16 PM Hamish Willee ***@***.***> wrote: *hamishwillee* left a comment (mdn/content#45256) <#45256 (comment)> @bbannon <https://github.com/bbannon> I can't see it listed twice in https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties/appearance Can you please screen shot and highlight the problematic part - or create a PR to fix it and cross link. — Reply to this email directly, view it on GitHub <#45256?email_source=notifications&email_token=AHJ7GLUHVRPX5NU5PH37HKT5K6IHDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMZWGM3DENBWGEZ2M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#issuecomment-5363624613>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHJ7GLRALRXKWXGWKK2GBY35K6IHDAVCNFSNUABFKJSXA33TNF2G64TZHMZDSNJXG42DGNZQHNEXG43VMU5TKMRQGA4TOMRTHA2KC5QC> . Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AHJ7GLVMZYFHGOZ4PGZH2LD5K6IHDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMZWGM3DENBWGEZ2M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android <https://github.com/notifications/mobile/android/AHJ7GLV3L6RPJJY4YNC3MZ35K6IHDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMZWGM3DENBWGEZ2M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you were mentioned.Message ID: ***@***.***>

[bbannon]

It didn't look like that when it was on my screen. Let's try this again. Attempting to send plain text without the links. 3rd and 7th items in list Formal syntax appearance = none | auto | base | < base-select | <compat-auto> | <compat-special> | base <

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On Thu, Aug 20, 2026 at 6:16 PM Hamish Willee ***@***.***> wrote: hamishwillee left a comment (mdn/content#45256) @bbannon I can't see it listed twice in https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties/appearance Can you please screen shot and highlight the problematic part - or create a PR to fix it and cross link. — Reply to this email directly, view it on GitHub, or unsubscribe. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS and Android. Download it today! You are receiving this because you were mentioned.Message ID: ***@***.***>