Merge pull request #3744 from MicrosoftDocs/user/pabrosse/scer-146

Add "Scoped custom element registries" in 146 RelNotes

Author: captainbrosset

microsoft-edge/web-platform/release-notes/146.md

@@ -23,8 +23,9 @@ To stay up-to-date and get the latest web platform features, download a preview
   * [`trigger-scope`](#trigger-scope)
   * [`meta name="text-scale"` element](#meta-nametext-scale-element)
 * [Web APIs](#web-apis)
-  * [LCP: match spec'd behavior for emitting candidates](#lcp-match-specd-behavior-for-emitting-candidates)
-  * [Navigation API: add post-commit handler from precommit](#navigation-api-add-post-commit-handler-from-precommit)
+  * [Scoped custom element registries](#scoped-custom-element-registries)
+  * [LCP matches spec'd behavior for emitting candidates](#lcp-matches-specd-behavior-for-emitting-candidates)
+  * [Navigation API: Add post-commit handler from precommit](#navigation-api-add-post-commit-handler-from-precommit)
   * [Selective Permissions Intervention](#selective-permissions-intervention)
   * [MIME type parameters are preserved in data URLs](#mime-type-parameters-are-preserved-in-data-urls)
   * [`Intl.Locale.prototype.variants`](#intllocaleprototypevariants)
@@ -123,7 +124,20 @@ The following new Web API features are included in Microsoft Edge.
 
 
 <!-- ------------------------------ -->
-#### LCP: match spec'd behavior for emitting candidates
+#### Scoped custom element registries
+
+You can now create custom element registries that are separate from the global `window.customElements` registry, by using the `CustomElementRegistry()` constructor.
+
+Creating custom registries is useful for allowing the coexistence of multiple custom elements that have the same tag name.
+
+For example, if you have two different versions of a library that both define a `<my-button>` custom element, you can create separate registries for each version of the library, to avoid naming conflicts.
+
+See also:
+* [CustomElementRegistry: CustomElementRegistry() constructor](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/CustomElementRegistry) at MDN.
+
+
+<!-- ------------------------------ -->
+#### LCP matches spec'd behavior for emitting candidates
 
 The Largest Contentful Paint (LCP) algorithm now emits candidates based on painted content.  This aligns the algorithm with the latest behavior per the specification.
 
@@ -134,7 +148,7 @@ See also:
 
 
 <!-- ------------------------------ -->
-#### Navigation API: add post-commit handler from precommit
+#### Navigation API: Add post-commit handler from precommit
 
 When handling a `navigate` event, you can now register post-commit work while executing precommit logic.