Add caniuse links or comments where the (normalized) IDs match

features/accelerometer.yml

@@ -1,6 +1,7 @@
 name: Accelerometer
 description: The `Accelerometer`, `LinearAccelerationSensor` and `GravitySensor` APIs read the acceleration applied to a device in three dimensions, either including the effect of gravity, without its effect, or only its effect, respectively.
 spec: https://w3c.github.io/accelerometer/
+caniuse: accelerometer
 group: sensors
 status:
   compute_from:

features/background-clip-text.yml

@@ -2,4 +2,5 @@
 name: "background-clip: text"
 description: "The `background-clip: text` CSS declaration draws the background underneath only the text in the element."
 spec: https://drafts.csswg.org/css-backgrounds-4/#background-clip
+caniuse: background-clip-text
 group: background

features/background-sync.yml

@@ -1,6 +1,7 @@
 name: Background sync
 description: The background synchronization API registers a service worker callback to run only when the device is no longer offline. You can use this to let users continue using your app while offline and synchronize with a server after reconnecting.
 spec: https://wicg.github.io/background-sync/spec/
+caniuse: background-sync
 status:
   compute_from: api.SyncManager
 compat_features:

features/gyroscope.yml

@@ -1,6 +1,7 @@
 name: Gyroscope
 description: The `Gyroscope` API reads the angular velocity of a device in three dimensions.
 spec: https://w3c.github.io/gyroscope/#gyroscope-interface
+caniuse: gyroscope
 group: sensors
 status:
   compute_from: api.Gyroscope

features/intl-plural-rules.yml

@@ -2,6 +2,7 @@ name: Intl.PluralRules
 description: "The `Intl.PluralRules` API creates a locale-aware object that tells you which of the language's pluralization rules apply based on a given number."
 group: intl
 spec: https://tc39.es/ecma402/#pluralrules-objects
+caniuse: intl-pluralrules
 status:
   compute_from: javascript.builtins.Intl.PluralRules
 compat_features:

features/json.yml

@@ -2,6 +2,7 @@ name: JSON
 description: The `JSON` API provides static methods for parsing values from and converting values to JavaScript Object Notation (JSON), a serialization format for objects, arrays, numbers, strings, Boolean values, and null.
 group: json
 spec: https://tc39.es/ecma262/multipage/structured-data.html#sec-json-object
+caniuse: json
 status:
   compute_from: javascript.builtins.JSON
 compat_features:

features/link-rel-preconnect.yml

@@ -1,6 +1,7 @@
 name: '<link rel="preconnect">'
 description: The `rel="preconnect"` attribute for the `<link>` HTML element is a hint to the browser that the page or user is likely to request resources from another origin, so the browser should preemptively start a connection to the `href` value's origin.
 spec: https://html.spec.whatwg.org/multipage/links.html#link-type-preconnect
+caniuse: link-rel-preconnect
 group: resource-hints
 compat_features:
   - html.elements.link.rel.preconnect

features/magnetometer.yml

@@ -1,6 +1,7 @@
 name: Magnetometer
 description: The `Magnetometer` API reads magnetic field sensor data from the device's magnetometer.
 spec: https://w3c.github.io/magnetometer/
+caniuse: magnetometer
 group: sensors
 compat_features:
   - api.Magnetometer

features/menu.yml

@@ -1,6 +1,8 @@
 name: <menu>
 description: The `<menu>` element represents an unordered list of action items (`<li>`), such as a toolbar. It is a semantic alternative to the `<ul>` element.
 spec: https://html.spec.whatwg.org/multipage/grouping-content.html#menus
+# https://caniuse.com/menu is not linked here because it's for the <menuitem>
+# element, a historical Firefox-only feature.
 group: html-elements
 # TODO: Tag relevant parts of api.HTMLLIElement when possible:
 # https://github.com/web-platform-dx/web-features/issues/1173

features/multi-column.yml

@@ -1,6 +1,7 @@
 name: Multi-column layout
 description: Multi-column layout flows an element's content across one or more columns in a single row, without affecting the `display` property of its children.
 spec: https://drafts.csswg.org/css-multicol-1/
+caniuse: multicolumn
 group: multi-column
 status:
   compute_from: css.properties.columns

features/mutation-events.yml

@@ -2,6 +2,7 @@ name: Mutation events
 description: Mutation events like `DOMSubtreeModified`, `DOMNodeInserted`, or `DOMNodeRemoved` fire when DOM changes occur.
 # The latest spec doesn't mention them at all anymore.
 spec: https://w3c.github.io/uievents/
+caniuse: mutation-events
 group: dom
 discouraged:
   removal_date: 2025-09-15

features/mutationobserver.yml

@@ -1,6 +1,7 @@
 name: MutationObserver
 description: The `MutationObserver` API watches for changes to the DOM tree and calls a callback function when DOM changes occur.
 spec: https://dom.spec.whatwg.org/#interface-mutationobserver
+caniuse: mutationobserver
 group: dom
 compat_features:
   - api.MutationObserver

features/orientation-sensor.yml

@@ -3,6 +3,7 @@ description: The `AbsoluteOrientationSensor` and `RelativeOrientationSensor` API
 spec:
   - https://w3c.github.io/orientation-sensor/#absoluteorientationsensor-interface
   - https://w3c.github.io/orientation-sensor/#relativeorientationsensor-interface
+caniuse: orientation-sensor
 group: sensors
 compat_features:
   - api.OrientationSensor

features/outline.yml

@@ -1,6 +1,8 @@
 name: outline
 description: The `outline` CSS shorthand sets the color, style, and width of a line around an element, outside of the border.
 spec: https://drafts.csswg.org/css-ui-4/#outline
+# https://caniuse.com/outline is not linked because it covers both shorthand and
+# longhands, which are split in web-features. TODO: merge the features.
 compat_features:
   - css.properties.outline
   - css.properties.outline.dashed

features/outlines.yml

@@ -1,8 +1,8 @@
 name: Outlines
 description: The `outline-color`, `outline-style`, and `outline-width` and `outline-offset` CSS properties style a line around an element, outside of the border.
 spec: https://drafts.csswg.org/css-ui-4/#outline
-# TODO: Caniuse support is close but would need to be reconciled.
-# caniuse: outline
+# https://caniuse.com/outline is not linked because it covers both shorthand and
+# longhands, which are split in web-features. TODO: merge the features.
 compat_features:
   - css.properties.outline-color
   - css.properties.outline-color.transparent

features/payment-request.yml

@@ -1,6 +1,7 @@
 name: Payment request
 description: The `PaymentRequest` API prompts the user to make a payment through the browser's user interface.
 spec: https://w3c.github.io/payment-request/
+caniuse: payment-request
 group: payments
 status:
   compute_from: api.PaymentRequest

features/pdf-viewer.yml

@@ -1,5 +1,7 @@
 name: pdfViewerEnabled
 description: The `navigator.pdfViewerEnabled` property is a boolean for whether the browser navigates to and shows a PDF in the browser window or downloads the PDF.
 spec: https://html.spec.whatwg.org/multipage/system-state.html#pdf-viewing-support
+# Note: https://caniuse.com/pdf-viewer is not linked because it covers the
+# built-in PDF viewer, which is much older than navigator.pdfViewerEnabled.
 compat_features:
   - api.Navigator.pdfViewerEnabled

features/prefers-color-scheme.yml

@@ -1,6 +1,7 @@
 name: prefers-color-scheme media query
 description: The `prefers-color-scheme` CSS media query sets styles based on the requested color scheme, light or dark.
 spec: https://drafts.csswg.org/mediaqueries-5/#prefers-color-scheme
+caniuse: prefers-color-scheme
 group: media-queries
 status:
   compute_from: css.at-rules.media.prefers-color-scheme

features/registerprotocolhandler.yml

@@ -1,6 +1,7 @@
 name: registerProtocolHandler
 description: "The `navigator.registerProtocolHandler()` method declares a site's ability to handle an address scheme (also known as a protocol). For example, an email site can register to open `mailto:` URLs or a VoIP site to open `tel:` URLs."
 spec: https://html.spec.whatwg.org/multipage/system-state.html#custom-handlers
+caniuse: registerprotocolhandler
 status:
   compute_from: api.Navigator.registerProtocolHandler
 compat_features:

features/template-literals.yml

@@ -1,6 +1,7 @@
 name: Template literals
 description: Template literals are literals delimited with backtick (<code>`</code>) characters, allowing for multi-line strings, string interpolation with embedded expressions, and special constructs called tagged templates.
 spec: https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-template-literals
+caniuse: template-literals
 group: javascript
 compat_features:
   - javascript.grammar.template_literals

features/upgrade-insecure-requests.yml

@@ -1,6 +1,7 @@
 name: Upgrade insecure requests
 description: The `Upgrade-Insecure-Requests` HTTP request header tells the server that the response should redirect to a secure (HTTPS) resource.
 spec: https://w3c.github.io/webappsec-upgrade-insecure-requests/
+caniuse: upgradeinsecurerequests
 group: security
 compat_features:
   - http.headers.Upgrade-Insecure-Requests

features/vibration.yml

@@ -1,5 +1,6 @@
 name: Vibration
 description: The `navigator.vibrate()` method makes a tactile alert, if the device is equipped with a haptic motor.
 spec: https://w3c.github.io/vibration/
+caniuse: vibration
 compat_features:
   - api.Navigator.vibrate

features/xml-serializer.yml

@@ -1,6 +1,8 @@
 name: XMLSerializer
 description: The `XMLSerializer` API provides the `serializeToString()` method to construct an XML string representing a DOM tree.
 spec: https://w3c.github.io/DOM-Parsing/#the-xmlserializer-interface
+# https://caniuse.com/xml-serializer is not linked because it covers all of
+# DOMParser, XMLSerializer, innerHTML, outerHTML and insertAdjacentHTML.
 group:
   - parsing-and-serialization
   - xml