diff --git a/lib/src/generator/templates.aot_renderers_for_html.dart b/lib/src/generator/templates.aot_renderers_for_html.dart
index bced76cacc..2663dd84d2 100644
--- a/lib/src/generator/templates.aot_renderers_for_html.dart
+++ b/lib/src/generator/templates.aot_renderers_for_html.dart
@@ -548,8 +548,6 @@ String renderEnum(EnumTemplateData context0) {
         </dl>
       </section>''');
   }
-  buffer.write('\n\n    ');
-  buffer.write(_renderEnum_partial_constructors_9(context2));
   buffer.writeln();
   if (context2.hasPublicEnumValues) {
     buffer.writeln();
@@ -561,7 +559,7 @@ String renderEnum(EnumTemplateData context0) {
     var context3 = context2.publicEnumValues;
     for (var context4 in context3) {
       buffer.write('\n            ');
-      buffer.write(_renderEnum_partial_constant_10(context4));
+      buffer.write(_renderEnum_partial_constant_9(context4));
     }
     buffer.writeln();
     buffer.write('''
@@ -569,24 +567,24 @@ String renderEnum(EnumTemplateData context0) {
       </section>''');
   }
   buffer.write('\n\n    ');
-  buffer.write(_renderEnum_partial_instance_fields_11(context2));
+  buffer.write(_renderEnum_partial_instance_fields_10(context2));
   buffer.write('\n    ');
-  buffer.write(_renderEnum_partial_instance_methods_12(context2));
+  buffer.write(_renderEnum_partial_instance_methods_11(context2));
   buffer.write('\n    ');
-  buffer.write(_renderEnum_partial_instance_operators_13(context2));
+  buffer.write(_renderEnum_partial_instance_operators_12(context2));
   buffer.write('\n    ');
-  buffer.write(_renderEnum_partial_static_properties_14(context2));
+  buffer.write(_renderEnum_partial_static_properties_13(context2));
   buffer.write('\n    ');
-  buffer.write(_renderEnum_partial_static_methods_15(context2));
+  buffer.write(_renderEnum_partial_static_methods_14(context2));
   buffer.write('\n    ');
-  buffer.write(_renderEnum_partial_static_constants_16(context2));
+  buffer.write(_renderEnum_partial_static_constants_15(context2));
   buffer.writeln();
   buffer.write('''
 </div><!-- /.main-content -->
 
 <div id="dartdoc-sidebar-left" class="sidebar sidebar-offcanvas-left">
   ''');
-  buffer.write(_renderEnum_partial_search_sidebar_17(context0));
+  buffer.write(_renderEnum_partial_search_sidebar_16(context0));
   buffer.writeln();
   buffer.write('''
   <h5>''');
@@ -601,7 +599,7 @@ String renderEnum(EnumTemplateData context0) {
 </div><!-- /.sidebar-offcanvas -->
 
 ''');
-  buffer.write(_renderEnum_partial_footer_18(context0));
+  buffer.write(_renderEnum_partial_footer_17(context0));
   buffer.writeln();
 
   return buffer.toString();
@@ -1696,7 +1694,7 @@ String renderSidebarForContainer<T extends Documentable>(
   buffer.write('''<ol>''');
   var context1 = context0.container;
   buffer.writeln();
-  if (context1.isClassOrEnum) {
+  if (context1.isClassOrExtensionType) {
     if (context1.hasPublicConstructors) {
       buffer.writeln();
       buffer.write('''
@@ -2706,34 +2704,31 @@ String _renderEnum_partial_mixed_in_types_7(Enum context1) {
 String _renderEnum_partial_container_annotations_8(Enum context1) =>
     _deduplicated_lib_templates__container_annotations_html(context1);
 
-String _renderEnum_partial_constructors_9(Enum context1) =>
-    _deduplicated_lib_templates__constructors_html(context1);
-
-String _renderEnum_partial_constant_10(Field context2) =>
+String _renderEnum_partial_constant_9(Field context2) =>
     _deduplicated_lib_templates__constant_html(context2);
 
-String _renderEnum_partial_instance_fields_11(Enum context1) =>
+String _renderEnum_partial_instance_fields_10(Enum context1) =>
     _deduplicated_lib_templates__instance_fields_html(context1);
 
-String _renderEnum_partial_instance_methods_12(Enum context1) =>
+String _renderEnum_partial_instance_methods_11(Enum context1) =>
     _deduplicated_lib_templates__instance_methods_html(context1);
 
-String _renderEnum_partial_instance_operators_13(Enum context1) =>
+String _renderEnum_partial_instance_operators_12(Enum context1) =>
     _deduplicated_lib_templates__instance_operators_html(context1);
 
-String _renderEnum_partial_static_properties_14(Enum context1) =>
+String _renderEnum_partial_static_properties_13(Enum context1) =>
     _deduplicated_lib_templates__static_properties_html(context1);
 
-String _renderEnum_partial_static_methods_15(Enum context1) =>
+String _renderEnum_partial_static_methods_14(Enum context1) =>
     _deduplicated_lib_templates__static_methods_html(context1);
 
-String _renderEnum_partial_static_constants_16(Enum context1) =>
+String _renderEnum_partial_static_constants_15(Enum context1) =>
     _deduplicated_lib_templates__static_constants_html(context1);
 
-String _renderEnum_partial_search_sidebar_17(EnumTemplateData context0) =>
+String _renderEnum_partial_search_sidebar_16(EnumTemplateData context0) =>
     _deduplicated_lib_templates__search_sidebar_html(context0);
 
-String _renderEnum_partial_footer_18(EnumTemplateData context0) =>
+String _renderEnum_partial_footer_17(EnumTemplateData context0) =>
     _deduplicated_lib_templates__footer_html(context0);
 
 String _renderError_partial_head_0(PackageTemplateData context0) =>
@@ -4417,8 +4412,7 @@ String _deduplicated_lib_templates__container_annotations_html(
   return buffer.toString();
 }
 
-String _deduplicated_lib_templates__constructors_html(
-    InheritingContainer context0) {
+String _deduplicated_lib_templates__constructors_html(Constructable context0) {
   final buffer = StringBuffer();
   if (context0.hasPublicConstructors) {
     buffer.writeln();
diff --git a/lib/src/generator/templates.runtime_renderers.dart b/lib/src/generator/templates.runtime_renderers.dart
index f1d7961fec..7e9fe11363 100644
--- a/lib/src/generator/templates.runtime_renderers.dart
+++ b/lib/src/generator/templates.runtime_renderers.dart
@@ -2936,6 +2936,13 @@ class _Renderer_Container extends RendererBase<Container> {
                       self.renderSimpleVariable(c, remainingNames, 'bool'),
                   getBool: (CT_ c) => c.isClassOrEnum,
                 ),
+                'isClassOrExtensionType': Property(
+                  getValue: (CT_ c) => c.isClassOrExtensionType,
+                  renderVariable: (CT_ c, Property<CT_> self,
+                          List<String> remainingNames) =>
+                      self.renderSimpleVariable(c, remainingNames, 'bool'),
+                  getBool: (CT_ c) => c.isClassOrExtensionType,
+                ),
                 'isEnum': Property(
                   getValue: (CT_ c) => c.isEnum,
                   renderVariable: (CT_ c, Property<CT_> self,
@@ -16294,7 +16301,12 @@ const _invisibleGetters = {
     'runtimeType',
     'superclassConstraints'
   },
-  'ModelNode': {'hashCode', 'runtimeType', 'sourceCode'},
+  'ModelNode': {
+    'commentReferenceData',
+    'hashCode',
+    'runtimeType',
+    'sourceCode'
+  },
   'PackageGraph': {
     'allConstructedModelElements',
     'allExtensionsAdded',
@@ -16482,6 +16494,7 @@ const _invisibleGetters = {
     'aliasedType',
     'enclosingElement',
     'hashCode',
+    'isAugmentation',
     'name',
     'runtimeType'
   },
diff --git a/lib/src/model/constructor.dart b/lib/src/model/constructor.dart
index 331ee6482d..94b229cdf5 100644
--- a/lib/src/model/constructor.dart
+++ b/lib/src/model/constructor.dart
@@ -31,15 +31,18 @@ class Constructor extends ModelElement with ContainerMember, TypeParameters {
     if (!super.isPublic) return false;
     if (element.hasPrivateName) return false;
     var class_ = element.enclosingElement;
-    if (class_ is! ClassElement) return true;
-    if (element.isFactory) return true;
-    if (class_.isSealed ||
-        (class_.isAbstract && class_.isFinal) ||
-        (class_.isAbstract && class_.isInterface)) {
-      /// Sealed classes, abstract final classes, and abstract interface
-      /// classes, cannot be instantiated nor extended, from outside the
-      /// declaring library. Avoid documenting them.
-      return false;
+    // Enums cannot be explicitly constructed or extended.
+    if (class_ is EnumElement) return false;
+    if (class_ is ClassElement) {
+      if (element.isFactory) return true;
+      if (class_.isSealed ||
+          (class_.isAbstract && class_.isFinal) ||
+          (class_.isAbstract && class_.isInterface)) {
+        /// Sealed classes, abstract final classes, and abstract interface
+        /// classes, cannot be instantiated nor extended, from outside the
+        /// declaring library. Avoid documenting them.
+        return false;
+      }
     }
     return true;
   }
diff --git a/lib/src/model/container.dart b/lib/src/model/container.dart
index 88def839d6..51ff52e8b7 100644
--- a/lib/src/model/container.dart
+++ b/lib/src/model/container.dart
@@ -53,6 +53,10 @@ abstract class Container extends ModelElement
   /// Whether this is a class or an enum.
   bool get isClassOrEnum => element is InterfaceElement;
 
+  /// Whether this is a class or an extension type.
+  bool get isClassOrExtensionType =>
+      element is ClassElement || element is ExtensionTypeElement;
+
   /// Whether this is a mixin.
   bool get isMixin => element is MixinElement;
 
diff --git a/lib/templates/_sidebar_for_container.html b/lib/templates/_sidebar_for_container.html
index 66d4d98369..35c7263526 100644
--- a/lib/templates/_sidebar_for_container.html
+++ b/lib/templates/_sidebar_for_container.html
@@ -1,14 +1,14 @@
 <ol>
   {{ #container }}
 
-    {{ #isClassOrEnum }}
+    {{ #isClassOrExtensionType }}
       {{ #hasPublicConstructors }}
         <li class="section-title"><a href="{{{ href }}}#constructors">Constructors</a></li>
         {{ #publicConstructorsSorted }}
           <li><a{{ #isDeprecated }} class="deprecated"{{ /isDeprecated }} href="{{{ href }}}">{{ shortName }}</a></li>
         {{ /publicConstructorsSorted }}
       {{ /hasPublicConstructors }}
-    {{ /isClassOrEnum }}
+    {{ /isClassOrExtensionType }}
 
     {{ #isEnum }}
       {{ #hasPublicEnumValues }}
diff --git a/lib/templates/enum.html b/lib/templates/enum.html
index 9b3fd3ee17..59eb913204 100644
--- a/lib/templates/enum.html
+++ b/lib/templates/enum.html
@@ -28,8 +28,6 @@ <h1>
       </section>
     {{ /hasModifiers }}
 
-    {{ >constructors }}
-
     {{ #hasPublicEnumValues }}
       <section class="summary offset-anchor" id="values">
         <h2>Values</h2>
diff --git a/test/constructors_test.dart b/test/constructors_test.dart
index 664b5d8b01..d6e9978a61 100644
--- a/test/constructors_test.dart
+++ b/test/constructors_test.dart
@@ -145,4 +145,78 @@ sealed class C {
     expect(c.isPublic, isFalse);
     expect(c.documentationAsHtml, '<p>Constructor.</p>');
   }
+
+  void test_enum_named() async {
+    var library = await bootPackageWithLibrary('''
+enum E {
+  one.named(), two.named();
+  /// Constructor.
+  const E.named();
+}
+''');
+    var e = library.enums.named('E').constructors.first;
+    expect(e.name, equals('E.named'));
+    expect(e.isPublic, isFalse);
+    expect(e.documentationAsHtml, '<p>Constructor.</p>');
+  }
+
+  void test_enum_unnamed() async {
+    var library = await bootPackageWithLibrary('''
+enum E {
+  one(), two();
+  /// Constructor.
+  const E();
+}
+''');
+    var e = library.enums.named('E').constructors.first;
+    expect(e.name, equals('E'));
+    expect(e.isPublic, isFalse);
+    expect(e.documentationAsHtml, '<p>Constructor.</p>');
+  }
+
+  void test_extensionType_named() async {
+    var library = await bootPackageWithLibrary('''
+extension type ET(int it) {
+  /// Constructor.
+  ET.named(this.it);
+}
+''');
+    var etNamed =
+        library.extensionTypes.named('ET').constructors.named('ET.named');
+    expect(etNamed.name, equals('ET.named'));
+    expect(etNamed.isPublic, isTrue);
+    expect(etNamed.documentationAsHtml, '<p>Constructor.</p>');
+  }
+
+  void test_extensionType_primaryNamed() async {
+    var library = await bootPackageWithLibrary('''
+extension type ET.named(int it) {}
+''');
+    var etNamed =
+        library.extensionTypes.named('ET').constructors.named('ET.named');
+    expect(etNamed.name, equals('ET.named'));
+    expect(etNamed.isPublic, isTrue);
+  }
+
+  void test_extensionType_primaryUnnamed() async {
+    var library = await bootPackageWithLibrary('''
+extension type ET(int it) {}
+''');
+    var et = library.extensionTypes.named('ET').constructors.named('ET');
+    expect(et.name, equals('ET'));
+    expect(et.isPublic, isTrue);
+  }
+
+  void test_extensionType_unnamed() async {
+    var library = await bootPackageWithLibrary('''
+extension type ET.named(int it) {
+  /// Constructor.
+  ET(this.it);
+}
+''');
+    var etNamed = library.extensionTypes.named('ET').constructors.named('ET');
+    expect(etNamed.name, equals('ET'));
+    expect(etNamed.isPublic, isTrue);
+    expect(etNamed.documentationAsHtml, '<p>Constructor.</p>');
+  }
 }
diff --git a/test/dartdoc_test_base.dart b/test/dartdoc_test_base.dart
index 835571eb8c..4bc7e764eb 100644
--- a/test/dartdoc_test_base.dart
+++ b/test/dartdoc_test_base.dart
@@ -38,7 +38,7 @@ abstract class DartdocTestBase {
 
   String get dartCoreUrlPrefix => 'https://api.dart.dev/stable/3.2.0/dart-core';
 
-  String get sdkConstraint => '>=3.2.0 <4.0.0';
+  String get sdkConstraint => '>=3.3.0 <4.0.0';
 
   List<String> get experiments => [];
 
diff --git a/test/enum_test.dart b/test/enum_test.dart
index 71ca8af6ed..6fc4640ddb 100644
--- a/test/enum_test.dart
+++ b/test/enum_test.dart
@@ -218,27 +218,6 @@ enum E<T> with M<T>, N { one, two, three; }
     expect(eEnum.mixedInElements.map((e) => e.name), equals(['M', 'N']));
   }
 
-  void test_namedConstructorCanBeReferenced() async {
-    // TODO(srawlins): As all supported Dart is >=2.15.0, this test can just
-    // be a "constructors" test rather than an "enum" test.
-    var library = await bootPackageWithLibrary('''
-enum E {
-  one.named(1),
-  two.named(2);
-
-  const E.named(int x);
-}
-
-/// Reference to [E.named].
-class C {}
-''');
-    var cClass = library.classes.named('C');
-    expect(
-      cClass.documentationAsHtml,
-      '<p>Reference to <a href="$linkPrefix/E/E.named.html">E.named</a>.</p>',
-    );
-  }
-
   void test_operatorsAreDocumented() async {
     // TODO(srawlins): As all supported Dart is >=2.15.0, this test can just
     // be an "operator" test rather than an "enum" test.
diff --git a/test/templates/enum_test.dart b/test/templates/enum_test.dart
index 8c36a3303f..ab30c295fb 100644
--- a/test/templates/enum_test.dart
+++ b/test/templates/enum_test.dart
@@ -17,7 +17,6 @@ void main() async {
   late List<String> eLines;
   late List<String> eRightSidebarLines;
   late List<String> enumWithDefaultConstructorLines;
-  late List<String> enumWithDefaultConstructorRightSidebarLines;
 
   group('enums', () {
     setUpAll(() async {
@@ -131,11 +130,6 @@ enum EnumWithDefaultConstructor {
               packagePath, 'doc', 'lib', 'EnumWithDefaultConstructor.html'))
           .readAsStringSync()
           .split('\n');
-      enumWithDefaultConstructorRightSidebarLines = resourceProvider
-          .getFile(path.join(packagePath, 'doc', 'lib',
-              'EnumWithDefaultConstructor-enum-sidebar.html'))
-          .readAsStringSync()
-          .split('\n');
     });
 
     test('enum page contains enum name with generics', () async {
@@ -342,29 +336,6 @@ enum EnumWithDefaultConstructor {
           ]));
     });
 
-    test('enum sidebar contains default constructors', () async {
-      expect(
-        enumWithDefaultConstructorRightSidebarLines,
-        containsAllInOrder([
-          matches('<a href="lib/EnumWithDefaultConstructor.html#constructors">'
-              'Constructors</a>'),
-          matches(
-              '<a href="lib/EnumWithDefaultConstructor/EnumWithDefaultConstructor.html">'
-              'EnumWithDefaultConstructor</a>'),
-        ]),
-      );
-    });
-
-    test('enum sidebar contains explicit constructors', () async {
-      expect(
-        eRightSidebarLines,
-        containsAllInOrder([
-          matches('<a href="lib/E.html#constructors">Constructors</a>'),
-          matches('<a href="lib/E/E.named.html">named</a>'),
-        ]),
-      );
-    });
-
     test('enum sidebar contains values', () async {
       expect(
         eRightSidebarLines,