demo · v150
named-feature() Registry Catalog
The named-feature() condition in @supports and CSS.supports() uses a curated registry of feature names defined by the CSS spec. This catalog lists every known name, probes each one live in your browser, and lets you test arbitrary names of your own.
CSS.supports('named-feature(name)') returns true only if the browser has implemented and enabled that specific registered identifier.
| Named Feature | Status in this browser | Registry entry | Description |
|---|
Test your own named-feature string
Enter an unquoted CSS identifier to probe CSS.supports('named-feature(…)') live:
/* Every named-feature() name is defined in the CSS spec registry.
The function takes an unquoted CSS identifier, not a string. */
@supports named-feature(anchor-position-follows-transforms) {
/* Anchor-positioned elements track their anchors through transforms.
This was the first officially-registered name. */
.tooltip { anchor-name: --target; }
.popup {
position: absolute;
position-anchor: --target;
top: anchor(bottom);
}
}
/* CSS.supports() form — same name, JavaScript-friendly */
const supported = CSS.supports('named-feature(anchor-position-follows-transforms)');
/* Combining with other @supports conditions */
@supports named-feature(anchor-position-follows-transforms) and (anchor-name: --x) {
/* Full anchor positioning, including transform-tracking */
}
/* Future names must be standardized — browsers cannot invent private names.
The registry ensures interoperable detection across browsers. */How the registry works
The CSS Conditional Rules Level 5 specification defines a named feature registry — a normative list of CSS identifiers that browsers are allowed to return true for. This is intentional: browsers cannot define private names. Any name a browser returns true for must appear in the spec registry, which ensures interoperable detection. Unrecognized names always return false.
The current editor's draft lists anchor-position-follows-transforms and single-axis-scroll-container. The spec mechanism is in place for rare future additions when a subtle behavior cannot be detected by property, selector, or at-rule probes.
see also
implementation reference
Need the exact API surface, compatibility boundaries, errors, lifecycle, and source links? Read the matching gendn reference ↗