CSS property 'list-style-type' supports two new keywords 'disclosure-open' and 'disclosure-closed'. In an element with display:list-item, 'disclosure-open' shows a symbol indicating a widget like <details> is opened. 'disclosure-closed' shows a symbol indicating a widget like <details> is closed. They will be used for the default style of <summary> in the user-agent stylesheet.


This is a step of standardizing a way to customize the appearance of the disclosure triangle of <details> and <summary>. 'disclosure-open' and 'disclosure-closed' will be used as the default style of <summary>. Web developers can use these keywords to reset the <summary> appearance, and to create a UI widget like <details>/<summary> with their own code.


Specification link

Specification being incubated in a Community Group

Status in Chromium


Enabled by default (tracking bug)

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.


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Last updated on 2021-12-13