diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
index d693a3cd6..26ae854e2 100644
--- a/baselines/dom.generated.d.ts
+++ b/baselines/dom.generated.d.ts
@@ -351,7 +351,7 @@ interface CSSNumericType {
 }
 
 interface CSSStyleSheetInit {
-    baseURL?: string;
+    baseURL?: string | null;
     disabled?: boolean;
     media?: MediaList | string;
 }
@@ -3152,6 +3152,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
@@ -5376,7 +5377,7 @@ declare var CSSCounterStyleRule: {
  */
 interface CSSFontFaceRule extends CSSRule {
     /**
-     * The read-only **`style`** property of the CSSFontFaceRule interface contains a CSSStyleDeclaration object representing the descriptors available in the @font-face rule's body.
+     * The read-only **`style`** property of the CSSFontFaceRule interface returns a CSSFontFaceDescriptors object representing the descriptors available in the @font-face rule's body.
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CSSFontFaceRule/style)
      */
@@ -7389,7 +7390,7 @@ interface CSSStyleProperties extends CSSStyleDeclarationBase {
      */
     columnWidth: string;
     /**
-     * The **`columns`** CSS shorthand property sets the number of columns to use when drawing an element's contents, as well as those columns' widths.
+     * The **`columns`** CSS shorthand property sets the maximum number of columns to use when drawing an element's contents, along with the minimum width and maximum height of the element's columns.
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/CSS/Reference/Properties/columns)
      */
@@ -11288,7 +11289,7 @@ declare var CryptoKey: {
 };
 
 /**
- * The **`CustomElementRegistry`** interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property.
+ * The **`CustomElementRegistry`** interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property. To create a scoped registry, use the CustomElementRegistry() constructor.
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry)
  */
@@ -11311,7 +11312,11 @@ interface CustomElementRegistry {
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/getName)
      */
     getName(constructor: CustomElementConstructor): string | null;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/initialize) */
+    /**
+     * The **`initialize()`** method of the CustomElementRegistry interface associates this registry with a DOM subtree, setting the customElementRegistry of each inclusive descendant that doesn't already have one, and attempting to upgrade any custom elements found.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/initialize)
+     */
     initialize(root: Node): void;
     /**
      * The **`upgrade()`** method of the CustomElementRegistry interface upgrades all shadow-containing custom elements in a Node subtree, even before they are connected to the main document.
@@ -13621,7 +13626,11 @@ interface Element extends Node, ARIAMixin, Animatable, ChildNode, NonDocumentTyp
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/currentCSSZoom)
      */
     readonly currentCSSZoom: number;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/customElementRegistry) */
+    /**
+     * The **`customElementRegistry`** read-only property of the Element interface returns the CustomElementRegistry object associated with this element, or null if one has not been set.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/customElementRegistry)
+     */
     readonly customElementRegistry: CustomElementRegistry | null;
     /**
      * The **`id`** property of the Element interface represents the element's identifier, reflecting the id global attribute.
@@ -17096,7 +17105,7 @@ declare var HTMLAllCollection: {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement)
  */
-interface HTMLAnchorElement extends HTMLElement, HTMLHyperlinkElementUtils {
+interface HTMLAnchorElement extends HTMLElement, HTMLHyperlinkElementUtils, HyperlinkElementUtils {
     /** @deprecated */
     charset: string;
     /** @deprecated */
@@ -17178,7 +17187,7 @@ declare var HTMLAnchorElement: {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAreaElement)
  */
-interface HTMLAreaElement extends HTMLElement, HTMLHyperlinkElementUtils {
+interface HTMLAreaElement extends HTMLElement, HTMLHyperlinkElementUtils, HyperlinkElementUtils {
     /**
      * The **`alt`** property of the HTMLAreaElement interface specifies the text of the hyperlink, defining the textual label for an image map's link. It reflects the <area> element's alt attribute.
      *
@@ -18430,30 +18439,6 @@ declare var HTMLHtmlElement: {
 };
 
 interface HTMLHyperlinkElementUtils {
-    /**
-     * Returns the hyperlink's URL's fragment (includes leading "#" if non-empty).
-     *
-     * Can be set, to change the URL's fragment (ignores leading "#").
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hash)
-     */
-    hash: string;
-    /**
-     * Returns the hyperlink's URL's host and port (if different from the default port for the scheme).
-     *
-     * Can be set, to change the URL's host and port.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/host)
-     */
-    host: string;
-    /**
-     * Returns the hyperlink's URL's host.
-     *
-     * Can be set, to change the URL's host.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hostname)
-     */
-    hostname: string;
     /**
      * Returns the hyperlink's URL.
      *
@@ -18463,60 +18448,6 @@ interface HTMLHyperlinkElementUtils {
      */
     href: string;
     toString(): string;
-    /**
-     * Returns the hyperlink's URL's origin.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/origin)
-     */
-    readonly origin: string;
-    /**
-     * Returns the hyperlink's URL's password.
-     *
-     * Can be set, to change the URL's password.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/password)
-     */
-    password: string;
-    /**
-     * Returns the hyperlink's URL's path.
-     *
-     * Can be set, to change the URL's path.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/pathname)
-     */
-    pathname: string;
-    /**
-     * Returns the hyperlink's URL's port.
-     *
-     * Can be set, to change the URL's port.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/port)
-     */
-    port: string;
-    /**
-     * Returns the hyperlink's URL's scheme.
-     *
-     * Can be set, to change the URL's scheme.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/protocol)
-     */
-    protocol: string;
-    /**
-     * Returns the hyperlink's URL's query (includes leading "?" if non-empty).
-     *
-     * Can be set, to change the URL's query (ignores leading "?").
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/search)
-     */
-    search: string;
-    /**
-     * Returns the hyperlink's URL's username.
-     *
-     * Can be set, to change the URL's username.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/username)
-     */
-    username: string;
 }
 
 /**
@@ -21399,7 +21330,11 @@ interface HTMLTemplateElement extends HTMLElement {
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootClonable)
      */
     shadowRootClonable: boolean;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry) */
+    /**
+     * The **`shadowRootCustomElementRegistry`** property of the HTMLTemplateElement interface reflects the value of the shadowrootcustomelementregistry attribute of the associated <template> element.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry)
+     */
     shadowRootCustomElementRegistry: string;
     /**
      * The **`shadowRootDelegatesFocus`** property of the HTMLTemplateElement interface reflects the value of the shadowrootdelegatesfocus attribute of the associated <template> element.
@@ -22047,6 +21982,29 @@ declare var History: {
     new(): History;
 };
 
+interface HyperlinkElementUtils {
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hash) */
+    hash: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/host) */
+    host: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hostname) */
+    hostname: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/origin) */
+    readonly origin: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/password) */
+    password: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/pathname) */
+    pathname: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/port) */
+    port: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/protocol) */
+    protocol: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/search) */
+    search: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/username) */
+    username: string;
+}
+
 /**
  * The **`IDBCursor`** interface of the IndexedDB API represents a cursor for traversing or iterating over multiple records in a database.
  *
diff --git a/baselines/serviceworker.generated.d.ts b/baselines/serviceworker.generated.d.ts
index 90b838669..8f3542a26 100644
--- a/baselines/serviceworker.generated.d.ts
+++ b/baselines/serviceworker.generated.d.ts
@@ -1235,6 +1235,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/sharedworker.generated.d.ts b/baselines/sharedworker.generated.d.ts
index dd83d4fdc..7a46c3356 100644
--- a/baselines/sharedworker.generated.d.ts
+++ b/baselines/sharedworker.generated.d.ts
@@ -1165,6 +1165,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.5/dom.generated.d.ts b/baselines/ts5.5/dom.generated.d.ts
index 2bc384392..6a6a193d1 100644
--- a/baselines/ts5.5/dom.generated.d.ts
+++ b/baselines/ts5.5/dom.generated.d.ts
@@ -348,7 +348,7 @@ interface CSSNumericType {
 }
 
 interface CSSStyleSheetInit {
-    baseURL?: string;
+    baseURL?: string | null;
     disabled?: boolean;
     media?: MediaList | string;
 }
@@ -3149,6 +3149,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
@@ -5373,7 +5374,7 @@ declare var CSSCounterStyleRule: {
  */
 interface CSSFontFaceRule extends CSSRule {
     /**
-     * The read-only **`style`** property of the CSSFontFaceRule interface contains a CSSStyleDeclaration object representing the descriptors available in the @font-face rule's body.
+     * The read-only **`style`** property of the CSSFontFaceRule interface returns a CSSFontFaceDescriptors object representing the descriptors available in the @font-face rule's body.
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CSSFontFaceRule/style)
      */
@@ -7379,7 +7380,7 @@ interface CSSStyleProperties extends CSSStyleDeclarationBase {
      */
     columnWidth: string;
     /**
-     * The **`columns`** CSS shorthand property sets the number of columns to use when drawing an element's contents, as well as those columns' widths.
+     * The **`columns`** CSS shorthand property sets the maximum number of columns to use when drawing an element's contents, along with the minimum width and maximum height of the element's columns.
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/CSS/Reference/Properties/columns)
      */
@@ -11277,7 +11278,7 @@ declare var CryptoKey: {
 };
 
 /**
- * The **`CustomElementRegistry`** interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property.
+ * The **`CustomElementRegistry`** interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property. To create a scoped registry, use the CustomElementRegistry() constructor.
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry)
  */
@@ -11300,7 +11301,11 @@ interface CustomElementRegistry {
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/getName)
      */
     getName(constructor: CustomElementConstructor): string | null;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/initialize) */
+    /**
+     * The **`initialize()`** method of the CustomElementRegistry interface associates this registry with a DOM subtree, setting the customElementRegistry of each inclusive descendant that doesn't already have one, and attempting to upgrade any custom elements found.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/initialize)
+     */
     initialize(root: Node): void;
     /**
      * The **`upgrade()`** method of the CustomElementRegistry interface upgrades all shadow-containing custom elements in a Node subtree, even before they are connected to the main document.
@@ -13609,7 +13614,11 @@ interface Element extends Node, ARIAMixin, Animatable, ChildNode, NonDocumentTyp
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/currentCSSZoom)
      */
     readonly currentCSSZoom: number;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/customElementRegistry) */
+    /**
+     * The **`customElementRegistry`** read-only property of the Element interface returns the CustomElementRegistry object associated with this element, or null if one has not been set.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/customElementRegistry)
+     */
     readonly customElementRegistry: CustomElementRegistry | null;
     /**
      * The **`id`** property of the Element interface represents the element's identifier, reflecting the id global attribute.
@@ -17082,7 +17091,7 @@ declare var HTMLAllCollection: {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement)
  */
-interface HTMLAnchorElement extends HTMLElement, HTMLHyperlinkElementUtils {
+interface HTMLAnchorElement extends HTMLElement, HTMLHyperlinkElementUtils, HyperlinkElementUtils {
     /** @deprecated */
     charset: string;
     /** @deprecated */
@@ -17163,7 +17172,7 @@ declare var HTMLAnchorElement: {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAreaElement)
  */
-interface HTMLAreaElement extends HTMLElement, HTMLHyperlinkElementUtils {
+interface HTMLAreaElement extends HTMLElement, HTMLHyperlinkElementUtils, HyperlinkElementUtils {
     /**
      * The **`alt`** property of the HTMLAreaElement interface specifies the text of the hyperlink, defining the textual label for an image map's link. It reflects the <area> element's alt attribute.
      *
@@ -18413,30 +18422,6 @@ declare var HTMLHtmlElement: {
 };
 
 interface HTMLHyperlinkElementUtils {
-    /**
-     * Returns the hyperlink's URL's fragment (includes leading "#" if non-empty).
-     *
-     * Can be set, to change the URL's fragment (ignores leading "#").
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hash)
-     */
-    hash: string;
-    /**
-     * Returns the hyperlink's URL's host and port (if different from the default port for the scheme).
-     *
-     * Can be set, to change the URL's host and port.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/host)
-     */
-    host: string;
-    /**
-     * Returns the hyperlink's URL's host.
-     *
-     * Can be set, to change the URL's host.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hostname)
-     */
-    hostname: string;
     /**
      * Returns the hyperlink's URL.
      *
@@ -18446,60 +18431,6 @@ interface HTMLHyperlinkElementUtils {
      */
     href: string;
     toString(): string;
-    /**
-     * Returns the hyperlink's URL's origin.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/origin)
-     */
-    readonly origin: string;
-    /**
-     * Returns the hyperlink's URL's password.
-     *
-     * Can be set, to change the URL's password.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/password)
-     */
-    password: string;
-    /**
-     * Returns the hyperlink's URL's path.
-     *
-     * Can be set, to change the URL's path.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/pathname)
-     */
-    pathname: string;
-    /**
-     * Returns the hyperlink's URL's port.
-     *
-     * Can be set, to change the URL's port.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/port)
-     */
-    port: string;
-    /**
-     * Returns the hyperlink's URL's scheme.
-     *
-     * Can be set, to change the URL's scheme.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/protocol)
-     */
-    protocol: string;
-    /**
-     * Returns the hyperlink's URL's query (includes leading "?" if non-empty).
-     *
-     * Can be set, to change the URL's query (ignores leading "?").
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/search)
-     */
-    search: string;
-    /**
-     * Returns the hyperlink's URL's username.
-     *
-     * Can be set, to change the URL's username.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/username)
-     */
-    username: string;
 }
 
 /**
@@ -21375,7 +21306,11 @@ interface HTMLTemplateElement extends HTMLElement {
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootClonable)
      */
     shadowRootClonable: boolean;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry) */
+    /**
+     * The **`shadowRootCustomElementRegistry`** property of the HTMLTemplateElement interface reflects the value of the shadowrootcustomelementregistry attribute of the associated <template> element.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry)
+     */
     shadowRootCustomElementRegistry: string;
     /**
      * The **`shadowRootDelegatesFocus`** property of the HTMLTemplateElement interface reflects the value of the shadowrootdelegatesfocus attribute of the associated <template> element.
@@ -22023,6 +21958,29 @@ declare var History: {
     new(): History;
 };
 
+interface HyperlinkElementUtils {
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hash) */
+    hash: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/host) */
+    host: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hostname) */
+    hostname: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/origin) */
+    readonly origin: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/password) */
+    password: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/pathname) */
+    pathname: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/port) */
+    port: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/protocol) */
+    protocol: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/search) */
+    search: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/username) */
+    username: string;
+}
+
 /**
  * The **`IDBCursor`** interface of the IndexedDB API represents a cursor for traversing or iterating over multiple records in a database.
  *
diff --git a/baselines/ts5.5/serviceworker.generated.d.ts b/baselines/ts5.5/serviceworker.generated.d.ts
index 9d420a826..0eb4ce4f4 100644
--- a/baselines/ts5.5/serviceworker.generated.d.ts
+++ b/baselines/ts5.5/serviceworker.generated.d.ts
@@ -1232,6 +1232,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.5/sharedworker.generated.d.ts b/baselines/ts5.5/sharedworker.generated.d.ts
index 72b0b45ae..861a76a0c 100644
--- a/baselines/ts5.5/sharedworker.generated.d.ts
+++ b/baselines/ts5.5/sharedworker.generated.d.ts
@@ -1162,6 +1162,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.5/webworker.generated.d.ts b/baselines/ts5.5/webworker.generated.d.ts
index 092fb7a1b..a519a726d 100644
--- a/baselines/ts5.5/webworker.generated.d.ts
+++ b/baselines/ts5.5/webworker.generated.d.ts
@@ -1481,6 +1481,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.6/dom.generated.d.ts b/baselines/ts5.6/dom.generated.d.ts
index ab9e0b25e..727be849f 100644
--- a/baselines/ts5.6/dom.generated.d.ts
+++ b/baselines/ts5.6/dom.generated.d.ts
@@ -348,7 +348,7 @@ interface CSSNumericType {
 }
 
 interface CSSStyleSheetInit {
-    baseURL?: string;
+    baseURL?: string | null;
     disabled?: boolean;
     media?: MediaList | string;
 }
@@ -3149,6 +3149,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
@@ -5373,7 +5374,7 @@ declare var CSSCounterStyleRule: {
  */
 interface CSSFontFaceRule extends CSSRule {
     /**
-     * The read-only **`style`** property of the CSSFontFaceRule interface contains a CSSStyleDeclaration object representing the descriptors available in the @font-face rule's body.
+     * The read-only **`style`** property of the CSSFontFaceRule interface returns a CSSFontFaceDescriptors object representing the descriptors available in the @font-face rule's body.
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CSSFontFaceRule/style)
      */
@@ -7386,7 +7387,7 @@ interface CSSStyleProperties extends CSSStyleDeclarationBase {
      */
     columnWidth: string;
     /**
-     * The **`columns`** CSS shorthand property sets the number of columns to use when drawing an element's contents, as well as those columns' widths.
+     * The **`columns`** CSS shorthand property sets the maximum number of columns to use when drawing an element's contents, along with the minimum width and maximum height of the element's columns.
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/CSS/Reference/Properties/columns)
      */
@@ -11285,7 +11286,7 @@ declare var CryptoKey: {
 };
 
 /**
- * The **`CustomElementRegistry`** interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property.
+ * The **`CustomElementRegistry`** interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property. To create a scoped registry, use the CustomElementRegistry() constructor.
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry)
  */
@@ -11308,7 +11309,11 @@ interface CustomElementRegistry {
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/getName)
      */
     getName(constructor: CustomElementConstructor): string | null;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/initialize) */
+    /**
+     * The **`initialize()`** method of the CustomElementRegistry interface associates this registry with a DOM subtree, setting the customElementRegistry of each inclusive descendant that doesn't already have one, and attempting to upgrade any custom elements found.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/initialize)
+     */
     initialize(root: Node): void;
     /**
      * The **`upgrade()`** method of the CustomElementRegistry interface upgrades all shadow-containing custom elements in a Node subtree, even before they are connected to the main document.
@@ -13618,7 +13623,11 @@ interface Element extends Node, ARIAMixin, Animatable, ChildNode, NonDocumentTyp
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/currentCSSZoom)
      */
     readonly currentCSSZoom: number;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/customElementRegistry) */
+    /**
+     * The **`customElementRegistry`** read-only property of the Element interface returns the CustomElementRegistry object associated with this element, or null if one has not been set.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/customElementRegistry)
+     */
     readonly customElementRegistry: CustomElementRegistry | null;
     /**
      * The **`id`** property of the Element interface represents the element's identifier, reflecting the id global attribute.
@@ -17093,7 +17102,7 @@ declare var HTMLAllCollection: {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement)
  */
-interface HTMLAnchorElement extends HTMLElement, HTMLHyperlinkElementUtils {
+interface HTMLAnchorElement extends HTMLElement, HTMLHyperlinkElementUtils, HyperlinkElementUtils {
     /** @deprecated */
     charset: string;
     /** @deprecated */
@@ -17175,7 +17184,7 @@ declare var HTMLAnchorElement: {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAreaElement)
  */
-interface HTMLAreaElement extends HTMLElement, HTMLHyperlinkElementUtils {
+interface HTMLAreaElement extends HTMLElement, HTMLHyperlinkElementUtils, HyperlinkElementUtils {
     /**
      * The **`alt`** property of the HTMLAreaElement interface specifies the text of the hyperlink, defining the textual label for an image map's link. It reflects the <area> element's alt attribute.
      *
@@ -18427,30 +18436,6 @@ declare var HTMLHtmlElement: {
 };
 
 interface HTMLHyperlinkElementUtils {
-    /**
-     * Returns the hyperlink's URL's fragment (includes leading "#" if non-empty).
-     *
-     * Can be set, to change the URL's fragment (ignores leading "#").
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hash)
-     */
-    hash: string;
-    /**
-     * Returns the hyperlink's URL's host and port (if different from the default port for the scheme).
-     *
-     * Can be set, to change the URL's host and port.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/host)
-     */
-    host: string;
-    /**
-     * Returns the hyperlink's URL's host.
-     *
-     * Can be set, to change the URL's host.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hostname)
-     */
-    hostname: string;
     /**
      * Returns the hyperlink's URL.
      *
@@ -18460,60 +18445,6 @@ interface HTMLHyperlinkElementUtils {
      */
     href: string;
     toString(): string;
-    /**
-     * Returns the hyperlink's URL's origin.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/origin)
-     */
-    readonly origin: string;
-    /**
-     * Returns the hyperlink's URL's password.
-     *
-     * Can be set, to change the URL's password.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/password)
-     */
-    password: string;
-    /**
-     * Returns the hyperlink's URL's path.
-     *
-     * Can be set, to change the URL's path.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/pathname)
-     */
-    pathname: string;
-    /**
-     * Returns the hyperlink's URL's port.
-     *
-     * Can be set, to change the URL's port.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/port)
-     */
-    port: string;
-    /**
-     * Returns the hyperlink's URL's scheme.
-     *
-     * Can be set, to change the URL's scheme.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/protocol)
-     */
-    protocol: string;
-    /**
-     * Returns the hyperlink's URL's query (includes leading "?" if non-empty).
-     *
-     * Can be set, to change the URL's query (ignores leading "?").
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/search)
-     */
-    search: string;
-    /**
-     * Returns the hyperlink's URL's username.
-     *
-     * Can be set, to change the URL's username.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/username)
-     */
-    username: string;
 }
 
 /**
@@ -21396,7 +21327,11 @@ interface HTMLTemplateElement extends HTMLElement {
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootClonable)
      */
     shadowRootClonable: boolean;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry) */
+    /**
+     * The **`shadowRootCustomElementRegistry`** property of the HTMLTemplateElement interface reflects the value of the shadowrootcustomelementregistry attribute of the associated <template> element.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry)
+     */
     shadowRootCustomElementRegistry: string;
     /**
      * The **`shadowRootDelegatesFocus`** property of the HTMLTemplateElement interface reflects the value of the shadowrootdelegatesfocus attribute of the associated <template> element.
@@ -22044,6 +21979,29 @@ declare var History: {
     new(): History;
 };
 
+interface HyperlinkElementUtils {
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hash) */
+    hash: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/host) */
+    host: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hostname) */
+    hostname: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/origin) */
+    readonly origin: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/password) */
+    password: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/pathname) */
+    pathname: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/port) */
+    port: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/protocol) */
+    protocol: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/search) */
+    search: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/username) */
+    username: string;
+}
+
 /**
  * The **`IDBCursor`** interface of the IndexedDB API represents a cursor for traversing or iterating over multiple records in a database.
  *
diff --git a/baselines/ts5.6/serviceworker.generated.d.ts b/baselines/ts5.6/serviceworker.generated.d.ts
index 9d420a826..0eb4ce4f4 100644
--- a/baselines/ts5.6/serviceworker.generated.d.ts
+++ b/baselines/ts5.6/serviceworker.generated.d.ts
@@ -1232,6 +1232,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.6/sharedworker.generated.d.ts b/baselines/ts5.6/sharedworker.generated.d.ts
index 72b0b45ae..861a76a0c 100644
--- a/baselines/ts5.6/sharedworker.generated.d.ts
+++ b/baselines/ts5.6/sharedworker.generated.d.ts
@@ -1162,6 +1162,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.6/webworker.generated.d.ts b/baselines/ts5.6/webworker.generated.d.ts
index 092fb7a1b..a519a726d 100644
--- a/baselines/ts5.6/webworker.generated.d.ts
+++ b/baselines/ts5.6/webworker.generated.d.ts
@@ -1481,6 +1481,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.9/dom.generated.d.ts b/baselines/ts5.9/dom.generated.d.ts
index e1cc9e73f..9a98853e1 100644
--- a/baselines/ts5.9/dom.generated.d.ts
+++ b/baselines/ts5.9/dom.generated.d.ts
@@ -348,7 +348,7 @@ interface CSSNumericType {
 }
 
 interface CSSStyleSheetInit {
-    baseURL?: string;
+    baseURL?: string | null;
     disabled?: boolean;
     media?: MediaList | string;
 }
@@ -3149,6 +3149,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
@@ -5373,7 +5374,7 @@ declare var CSSCounterStyleRule: {
  */
 interface CSSFontFaceRule extends CSSRule {
     /**
-     * The read-only **`style`** property of the CSSFontFaceRule interface contains a CSSStyleDeclaration object representing the descriptors available in the @font-face rule's body.
+     * The read-only **`style`** property of the CSSFontFaceRule interface returns a CSSFontFaceDescriptors object representing the descriptors available in the @font-face rule's body.
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CSSFontFaceRule/style)
      */
@@ -7386,7 +7387,7 @@ interface CSSStyleProperties extends CSSStyleDeclarationBase {
      */
     columnWidth: string;
     /**
-     * The **`columns`** CSS shorthand property sets the number of columns to use when drawing an element's contents, as well as those columns' widths.
+     * The **`columns`** CSS shorthand property sets the maximum number of columns to use when drawing an element's contents, along with the minimum width and maximum height of the element's columns.
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/CSS/Reference/Properties/columns)
      */
@@ -11285,7 +11286,7 @@ declare var CryptoKey: {
 };
 
 /**
- * The **`CustomElementRegistry`** interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property.
+ * The **`CustomElementRegistry`** interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property. To create a scoped registry, use the CustomElementRegistry() constructor.
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry)
  */
@@ -11308,7 +11309,11 @@ interface CustomElementRegistry {
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/getName)
      */
     getName(constructor: CustomElementConstructor): string | null;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/initialize) */
+    /**
+     * The **`initialize()`** method of the CustomElementRegistry interface associates this registry with a DOM subtree, setting the customElementRegistry of each inclusive descendant that doesn't already have one, and attempting to upgrade any custom elements found.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/CustomElementRegistry/initialize)
+     */
     initialize(root: Node): void;
     /**
      * The **`upgrade()`** method of the CustomElementRegistry interface upgrades all shadow-containing custom elements in a Node subtree, even before they are connected to the main document.
@@ -13618,7 +13623,11 @@ interface Element extends Node, ARIAMixin, Animatable, ChildNode, NonDocumentTyp
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/currentCSSZoom)
      */
     readonly currentCSSZoom: number;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/customElementRegistry) */
+    /**
+     * The **`customElementRegistry`** read-only property of the Element interface returns the CustomElementRegistry object associated with this element, or null if one has not been set.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Element/customElementRegistry)
+     */
     readonly customElementRegistry: CustomElementRegistry | null;
     /**
      * The **`id`** property of the Element interface represents the element's identifier, reflecting the id global attribute.
@@ -17093,7 +17102,7 @@ declare var HTMLAllCollection: {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement)
  */
-interface HTMLAnchorElement extends HTMLElement, HTMLHyperlinkElementUtils {
+interface HTMLAnchorElement extends HTMLElement, HTMLHyperlinkElementUtils, HyperlinkElementUtils {
     /** @deprecated */
     charset: string;
     /** @deprecated */
@@ -17175,7 +17184,7 @@ declare var HTMLAnchorElement: {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAreaElement)
  */
-interface HTMLAreaElement extends HTMLElement, HTMLHyperlinkElementUtils {
+interface HTMLAreaElement extends HTMLElement, HTMLHyperlinkElementUtils, HyperlinkElementUtils {
     /**
      * The **`alt`** property of the HTMLAreaElement interface specifies the text of the hyperlink, defining the textual label for an image map's link. It reflects the <area> element's alt attribute.
      *
@@ -18427,30 +18436,6 @@ declare var HTMLHtmlElement: {
 };
 
 interface HTMLHyperlinkElementUtils {
-    /**
-     * Returns the hyperlink's URL's fragment (includes leading "#" if non-empty).
-     *
-     * Can be set, to change the URL's fragment (ignores leading "#").
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hash)
-     */
-    hash: string;
-    /**
-     * Returns the hyperlink's URL's host and port (if different from the default port for the scheme).
-     *
-     * Can be set, to change the URL's host and port.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/host)
-     */
-    host: string;
-    /**
-     * Returns the hyperlink's URL's host.
-     *
-     * Can be set, to change the URL's host.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hostname)
-     */
-    hostname: string;
     /**
      * Returns the hyperlink's URL.
      *
@@ -18460,60 +18445,6 @@ interface HTMLHyperlinkElementUtils {
      */
     href: string;
     toString(): string;
-    /**
-     * Returns the hyperlink's URL's origin.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/origin)
-     */
-    readonly origin: string;
-    /**
-     * Returns the hyperlink's URL's password.
-     *
-     * Can be set, to change the URL's password.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/password)
-     */
-    password: string;
-    /**
-     * Returns the hyperlink's URL's path.
-     *
-     * Can be set, to change the URL's path.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/pathname)
-     */
-    pathname: string;
-    /**
-     * Returns the hyperlink's URL's port.
-     *
-     * Can be set, to change the URL's port.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/port)
-     */
-    port: string;
-    /**
-     * Returns the hyperlink's URL's scheme.
-     *
-     * Can be set, to change the URL's scheme.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/protocol)
-     */
-    protocol: string;
-    /**
-     * Returns the hyperlink's URL's query (includes leading "?" if non-empty).
-     *
-     * Can be set, to change the URL's query (ignores leading "?").
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/search)
-     */
-    search: string;
-    /**
-     * Returns the hyperlink's URL's username.
-     *
-     * Can be set, to change the URL's username.
-     *
-     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/username)
-     */
-    username: string;
 }
 
 /**
@@ -21396,7 +21327,11 @@ interface HTMLTemplateElement extends HTMLElement {
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootClonable)
      */
     shadowRootClonable: boolean;
-    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry) */
+    /**
+     * The **`shadowRootCustomElementRegistry`** property of the HTMLTemplateElement interface reflects the value of the shadowrootcustomelementregistry attribute of the associated <template> element.
+     *
+     * [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry)
+     */
     shadowRootCustomElementRegistry: string;
     /**
      * The **`shadowRootDelegatesFocus`** property of the HTMLTemplateElement interface reflects the value of the shadowrootdelegatesfocus attribute of the associated <template> element.
@@ -22044,6 +21979,29 @@ declare var History: {
     new(): History;
 };
 
+interface HyperlinkElementUtils {
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hash) */
+    hash: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/host) */
+    host: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/hostname) */
+    hostname: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/origin) */
+    readonly origin: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/password) */
+    password: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/pathname) */
+    pathname: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/port) */
+    port: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/protocol) */
+    protocol: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/search) */
+    search: string;
+    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/HTMLAnchorElement/username) */
+    username: string;
+}
+
 /**
  * The **`IDBCursor`** interface of the IndexedDB API represents a cursor for traversing or iterating over multiple records in a database.
  *
diff --git a/baselines/ts5.9/serviceworker.generated.d.ts b/baselines/ts5.9/serviceworker.generated.d.ts
index 3785996a6..82c4c74c4 100644
--- a/baselines/ts5.9/serviceworker.generated.d.ts
+++ b/baselines/ts5.9/serviceworker.generated.d.ts
@@ -1232,6 +1232,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.9/sharedworker.generated.d.ts b/baselines/ts5.9/sharedworker.generated.d.ts
index a447ef65a..f73077578 100644
--- a/baselines/ts5.9/sharedworker.generated.d.ts
+++ b/baselines/ts5.9/sharedworker.generated.d.ts
@@ -1162,6 +1162,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/ts5.9/webworker.generated.d.ts b/baselines/ts5.9/webworker.generated.d.ts
index 308626981..793e0307e 100644
--- a/baselines/ts5.9/webworker.generated.d.ts
+++ b/baselines/ts5.9/webworker.generated.d.ts
@@ -1481,6 +1481,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/baselines/webworker.generated.d.ts b/baselines/webworker.generated.d.ts
index 293996edb..d44bb9858 100644
--- a/baselines/webworker.generated.d.ts
+++ b/baselines/webworker.generated.d.ts
@@ -1484,6 +1484,7 @@ interface WebTransportHash {
 interface WebTransportOptions {
     allowPooling?: boolean;
     congestionControl?: WebTransportCongestionControl;
+    headers?: HeadersInit;
     protocols?: string[];
     requireUnreliable?: boolean;
     serverCertificateHashes?: WebTransportHash[];
diff --git a/inputfiles/mdn.json b/inputfiles/mdn.json
index fbb420f6d..20dc9a2fa 100644
--- a/inputfiles/mdn.json
+++ b/inputfiles/mdn.json
@@ -4044,6 +4044,11 @@
     "pageType": "web-api-instance-property",
     "summary": "The system property of the CSSCounterStyleRule interface gets and sets the value of the system descriptor. If the descriptor does not have a value set, this attribute returns an empty string."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/API/CSSFontFaceDescriptors",
+    "pageType": "web-api-interface",
+    "summary": "The CSSFontFaceDescriptors interface represents a CSS declaration block for an @font-face at-rule."
+  },
   {
     "mdn_url": "/en-US/docs/Web/API/CSSFontFaceRule",
     "pageType": "web-api-interface",
@@ -4052,7 +4057,7 @@
   {
     "mdn_url": "/en-US/docs/Web/API/CSSFontFaceRule/style",
     "pageType": "web-api-instance-property",
-    "summary": "The read-only style property of the CSSFontFaceRule interface contains a CSSStyleDeclaration object representing the descriptors available in the @font-face rule's body."
+    "summary": "The read-only style property of the CSSFontFaceRule interface returns a CSSFontFaceDescriptors object representing the descriptors available in the @font-face rule's body."
   },
   {
     "mdn_url": "/en-US/docs/Web/API/CSSFontFeatureValuesMap",
@@ -5297,7 +5302,12 @@
   {
     "mdn_url": "/en-US/docs/Web/API/CustomElementRegistry",
     "pageType": "web-api-interface",
-    "summary": "The CustomElementRegistry interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property."
+    "summary": "The CustomElementRegistry interface provides methods for registering custom elements and querying registered elements. To get an instance of it, use the window.customElements property. To create a scoped registry, use the CustomElementRegistry() constructor."
+  },
+  {
+    "mdn_url": "/en-US/docs/Web/API/CustomElementRegistry/CustomElementRegistry",
+    "pageType": "web-api-constructor",
+    "summary": "The CustomElementRegistry() constructor creates a new CustomElementRegistry object for scoped usage."
   },
   {
     "mdn_url": "/en-US/docs/Web/API/CustomElementRegistry/define",
@@ -5314,6 +5324,11 @@
     "pageType": "web-api-instance-method",
     "summary": "The getName() method of the\nCustomElementRegistry interface returns the name for a\npreviously-defined custom element."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/API/CustomElementRegistry/initialize",
+    "pageType": "web-api-instance-method",
+    "summary": "The initialize() method of the CustomElementRegistry interface associates this registry with a DOM subtree, setting the customElementRegistry of each inclusive descendant that doesn't already have one, and attempting to upgrade any custom elements found."
+  },
   {
     "mdn_url": "/en-US/docs/Web/API/CustomElementRegistry/upgrade",
     "pageType": "web-api-instance-method",
@@ -6104,6 +6119,11 @@
     "pageType": "web-api-instance-property",
     "summary": "The Document.currentScript property returns the <script> element whose script is currently being processed and isn't a JavaScript module. (For modules use import.meta instead.)"
   },
+  {
+    "mdn_url": "/en-US/docs/Web/API/Document/customElementRegistry",
+    "pageType": "web-api-instance-property",
+    "summary": "The customElementRegistry read-only property of the Document interface returns the CustomElementRegistry object associated with this document, or null if one has not been set."
+  },
   {
     "mdn_url": "/en-US/docs/Web/API/Document/defaultView",
     "pageType": "web-api-instance-property",
@@ -6582,7 +6602,7 @@
   {
     "mdn_url": "/en-US/docs/Web/API/Document/visibilitychange_event",
     "pageType": "web-api-event",
-    "summary": "The visibilitychange event is fired at the document when the contents of its tab have become visible or have been hidden."
+    "summary": "The visibilitychange event is fired at the document when its visibility status changes — for example, when the user switches browser tabs, navigates to a new page, minimizes or closes the browser, or on mobile, switches to a different app."
   },
   {
     "mdn_url": "/en-US/docs/Web/API/Document/visibilityState",
@@ -8009,6 +8029,11 @@
     "pageType": "web-api-instance-property",
     "summary": "The currentCSSZoom read-only property of the Element interface provides the \"effective\" CSS zoom of an element, taking into account the zoom applied to the element and all its parent elements."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/API/Element/customElementRegistry",
+    "pageType": "web-api-instance-property",
+    "summary": "The customElementRegistry read-only property of the Element interface returns the CustomElementRegistry object associated with this element, or null if one has not been set."
+  },
   {
     "mdn_url": "/en-US/docs/Web/API/Element/cut_event",
     "pageType": "web-api-event",
@@ -15629,6 +15654,11 @@
     "pageType": "web-api-instance-property",
     "summary": "The shadowRootClonable property reflects the value of the shadowrootclonable attribute of the associated <template> element."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/API/HTMLTemplateElement/shadowRootCustomElementRegistry",
+    "pageType": "web-api-instance-property",
+    "summary": "The shadowRootCustomElementRegistry property of the HTMLTemplateElement interface reflects the value of the shadowrootcustomelementregistry attribute of the associated <template> element."
+  },
   {
     "mdn_url": "/en-US/docs/Web/API/HTMLTemplateElement/shadowRootDelegatesFocus",
     "pageType": "web-api-instance-property",
@@ -17029,6 +17059,11 @@
     "pageType": "web-api-instance-property",
     "summary": "The boundingClientRect read-only property of the IntersectionObserverEntry interface returns a DOMRectReadOnly which in essence describes a rectangle describing the smallest rectangle that contains the entire target element."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/API/IntersectionObserverEntry/IntersectionObserverEntry",
+    "pageType": "web-api-constructor",
+    "summary": "The IntersectionObserverEntry() constructor creates and returns a new IntersectionObserverEntry object."
+  },
   {
     "mdn_url": "/en-US/docs/Web/API/IntersectionObserverEntry/intersectionRatio",
     "pageType": "web-api-instance-property",
@@ -27439,6 +27474,11 @@
     "pageType": "web-api-instance-property",
     "summary": "The clonable read-only property of the ShadowRoot interface returns true if the shadow root is clonable, and false otherwise."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/API/ShadowRoot/customElementRegistry",
+    "pageType": "web-api-instance-property",
+    "summary": "The customElementRegistry read-only property of the ShadowRoot interface returns the CustomElementRegistry object associated with this shadow root, or null if one has not been set."
+  },
   {
     "mdn_url": "/en-US/docs/Web/API/ShadowRoot/delegatesFocus",
     "pageType": "web-api-instance-property",
@@ -40339,6 +40379,11 @@
     "pageType": "css-property",
     "summary": "The column-gap CSS property sets the size of the gap (gutter) between an element's columns."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/column-height",
+    "pageType": "css-property",
+    "summary": "The column-height CSS property specifies the height of the columns in a CSS multi-column layout."
+  },
   {
     "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/column-rule",
     "pageType": "css-shorthand-property",
@@ -40369,10 +40414,15 @@
     "pageType": "css-property",
     "summary": "The column-width CSS property sets the ideal column width in a multi-column layout. The container will have as many columns as can fit without any of them having a width less than the column-width value. If the width of the container is narrower than the specified value, the single column's width will be smaller than the declared column width."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/column-wrap",
+    "pageType": "css-property",
+    "summary": "The column-wrap CSS property specifies the wrapping behavior of overflow columns in a CSS multi-column layout."
+  },
   {
     "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/columns",
     "pageType": "css-shorthand-property",
-    "summary": "The columns CSS shorthand property sets the number of columns to use when drawing an element's contents, as well as those columns' widths."
+    "summary": "The columns CSS shorthand property sets the maximum number of columns to use when drawing an element's contents, along with the minimum width and maximum height of the element's columns."
   },
   {
     "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/contain",
@@ -40789,6 +40839,11 @@
     "pageType": "css-property",
     "summary": "The font-weight CSS property sets the weight (or boldness) of the font. The weights available depend on the font-family that is currently set."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/font-width",
+    "pageType": "css-property",
+    "summary": "The font-width CSS property selects a normal, condensed, or expanded face from a font."
+  },
   {
     "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/forced-color-adjust",
     "pageType": "css-property",
@@ -41664,6 +41719,11 @@
     "pageType": "css-property",
     "summary": "The scroll-behavior CSS property sets the behavior for a scrolling box when scrolling is triggered by the navigation or CSSOM scrolling APIs."
   },
+  {
+    "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/scroll-initial-target",
+    "pageType": "css-property",
+    "summary": "The scroll-initial-target CSS property enables the definition of elements that are potential snap targets when their ancestor scroll container is first rendered."
+  },
   {
     "mdn_url": "/en-US/docs/Web/CSS/Reference/Properties/scroll-margin",
     "pageType": "css-shorthand-property",
diff --git a/package-lock.json b/package-lock.json
index 942e2fd8c..3509e6388 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1083,9 +1083,9 @@
       ]
     },
     "node_modules/@webref/css": {
-      "version": "8.2.6",
-      "resolved": "https://registry.npmjs.org/@webref/css/-/css-8.2.6.tgz",
-      "integrity": "sha512-flRhQOW+6Wq8Fgv6C+TlnWQyZSPQVQSowh7dEmox8LctVIbKv1pKq6pGDKNK2o3H8yxUjNu+IKGBnyd30e35/A==",
+      "version": "8.3.0",
+      "resolved": "https://registry.npmjs.org/@webref/css/-/css-8.3.0.tgz",
+      "integrity": "sha512-3BRRaPsajZe4GfiOO4C6jQJdzlAC38AUX70fKk6+ehpw/7D3AM0F5phHS/xqueFCdsnq9gKC9nIEwpBQ06FDew==",
       "dev": true,
       "license": "MIT",
       "peerDependencies": {
@@ -1100,16 +1100,16 @@
       "license": "MIT"
     },
     "node_modules/@webref/events": {
-      "version": "1.20.2",
-      "resolved": "https://registry.npmjs.org/@webref/events/-/events-1.20.2.tgz",
-      "integrity": "sha512-Aw3S55D8cApJWgOpDZjSIacyz+87jrVxnI3pks8k86pHSs5aEfCd8pvdXXslnqPziE2rl3CJzHx6oEK3LGYz/Q==",
+      "version": "1.21.0",
+      "resolved": "https://registry.npmjs.org/@webref/events/-/events-1.21.0.tgz",
+      "integrity": "sha512-GFi8NvwWwmNfteJg5uNU/b+4cp20d0lA5nBU46+VMRyPysJ/Z7KqppPQRxh4PbZ9bUDCcHC0p8PtCVu1iy38Pg==",
       "dev": true,
       "license": "MIT"
     },
     "node_modules/@webref/idl": {
-      "version": "3.73.0",
-      "resolved": "https://registry.npmjs.org/@webref/idl/-/idl-3.73.0.tgz",
-      "integrity": "sha512-B9SUkmz9rH97n625xhh4MsXsQTwLbLsZcM+VD+Uf7Jdpr3m+FLNeP+F5QYC+nujotik1aK28tPGLiBRQ1jVsSg==",
+      "version": "3.73.2",
+      "resolved": "https://registry.npmjs.org/@webref/idl/-/idl-3.73.2.tgz",
+      "integrity": "sha512-vX+wczckG7Nm4sdqh99OSbbmGeV164FDHl9EAhDC8qL1Z3ZMWBpKoeMEh+wgTLe3RtTKUyScwIwr0QMi+H3HXw==",
       "dev": true,
       "license": "MIT",
       "peerDependencies": {