diff --git a/code/AdminRootController.php b/code/AdminRootController.php
index bad63473c..32fade435 100644
--- a/code/AdminRootController.php
+++ b/code/AdminRootController.php
@@ -41,7 +41,7 @@ public static function get_admin_route()
      */
     public static function admin_url(string $action = '')
     {
-        return Controller::join_links(self::get_admin_route(), $action);
+        return Controller::join_links(AdminRootController::get_admin_route(), $action);
     }
 
     /**
@@ -69,18 +69,18 @@ public static function admin_url(string $action = '')
      */
     public static function rules()
     {
-        if (self::$adminRules === null) {
-            self::$adminRules = [];
+        if (AdminRootController::$adminRules === null) {
+            AdminRootController::$adminRules = [];
 
             // Map over the array calling add_rule_for_controller on each
             $classes = CMSMenu::get_cms_classes(null, true, CMSMenu::URL_PRIORITY);
             array_map([__CLASS__, 'add_rule_for_controller'], $classes ?? []);
         }
-        return self::$adminRules;
+        return AdminRootController::$adminRules;
     }
 
     /**
-     * Add the appropriate k/v pair to self::$rules for the given controller.
+     * Add the appropriate k/v pair to AdminRootController::$rules for the given controller.
      *
      * @param string $controllerClass Name of class
      */
@@ -98,8 +98,8 @@ protected static function add_rule_for_controller($controllerClass)
             $rule = $urlSegment . '//' . $urlRule;
 
             // ensure that the first call to add_rule_for_controller for a rule takes precedence
-            if (!isset(self::$adminRules[$rule])) {
-                self::$adminRules[$rule] = $controllerClass;
+            if (!isset(AdminRootController::$adminRules[$rule])) {
+                AdminRootController::$adminRules[$rule] = $controllerClass;
             }
         }
     }
@@ -111,12 +111,12 @@ public function handleRequest(HTTPRequest $request): HTTPResponse
             $segment = Config::forClass($this->config()->get('default_panel'))
                 ->get('url_segment');
 
-            $this->redirect(Controller::join_links(self::admin_url(), $segment, '/'));
+            $this->redirect(Controller::join_links(AdminRootController::admin_url(), $segment, '/'));
             return $this->getResponse();
         }
 
         // Otherwise
-        $rules = self::rules();
+        $rules = AdminRootController::rules();
         foreach ($rules as $pattern => $controller) {
             if (($arguments = $request->match($pattern, true)) !== false) {
                 /** @var LeftAndMain $controllerObj */
diff --git a/code/CMSMenu.php b/code/CMSMenu.php
index 20b00163e..0318dda0a 100644
--- a/code/CMSMenu.php
+++ b/code/CMSMenu.php
@@ -63,7 +63,7 @@ class CMSMenu implements IteratorAggregate, i18nEntityProvider
      */
     public static function populate_menu()
     {
-        self::$menu_is_cleared = false;
+        CMSMenu::$menu_is_cleared = false;
     }
 
     /**
@@ -73,9 +73,9 @@ public static function populate_menu()
      */
     public static function add_controller($controllerClass)
     {
-        if ($menuItem = self::menuitem_for_controller($controllerClass)) {
+        if ($menuItem = CMSMenu::menuitem_for_controller($controllerClass)) {
             $code = static::get_menu_code($controllerClass);
-            self::add_menu_item_obj($code, $menuItem);
+            CMSMenu::add_menu_item_obj($code, $menuItem);
         }
     }
 
@@ -123,7 +123,7 @@ protected static function menuitem_for_controller($controllerClass)
      */
     public static function add_link($code, $menuTitle, $url, $priority = -1, $attributes = null, $iconClass = null)
     {
-        return self::add_menu_item($code, $menuTitle, $url, null, $priority, $attributes, $iconClass);
+        return CMSMenu::add_menu_item($code, $menuTitle, $url, null, $priority, $attributes, $iconClass);
     }
 
     /**
@@ -155,10 +155,10 @@ public static function add_menu_item(
     ) {
         // If a class is defined, then force the use of that as a code.  This helps prevent menu item duplication
         if ($controllerClass) {
-            $code = self::get_menu_code($controllerClass);
+            $code = CMSMenu::get_menu_code($controllerClass);
         }
 
-        return self::replace_menu_item(
+        return CMSMenu::replace_menu_item(
             $code,
             $menuTitle,
             $url,
@@ -177,7 +177,7 @@ public static function add_menu_item(
      */
     public static function get_menu_item($code)
     {
-        $menuItems = self::get_menu_items();
+        $menuItems = CMSMenu::get_menu_items();
         return (isset($menuItems[$code])) ? $menuItems[$code] : false;
     }
 
@@ -202,11 +202,11 @@ public static function get_menu_items()
         $menuItems = [];
 
         // Set up default menu items
-        if (!self::$menu_is_cleared) {
-            $cmsClasses = self::get_cms_classes();
+        if (!CMSMenu::$menu_is_cleared) {
+            $cmsClasses = CMSMenu::get_cms_classes();
             foreach ($cmsClasses as $cmsClass) {
-                $menuItem = self::menuitem_for_controller($cmsClass);
-                $menuCode = self::get_menu_code($cmsClass);
+                $menuItem = CMSMenu::menuitem_for_controller($cmsClass);
+                $menuCode = CMSMenu::get_menu_code($cmsClass);
                 if ($menuItem) {
                     $menuItems[$menuCode] = $menuItem;
                 }
@@ -214,7 +214,7 @@ public static function get_menu_items()
         }
 
         // Apply changes
-        foreach (self::$menu_item_changes as $change) {
+        foreach (CMSMenu::$menu_item_changes as $change) {
             switch ($change['type']) {
                 case 'add':
                     $menuItems[$change['code']] = $change['item'];
@@ -255,7 +255,7 @@ public static function get_viewable_menu_items($member = null)
         }
 
         $viewableMenuItems = [];
-        $allMenuItems = self::get_menu_items();
+        $allMenuItems = CMSMenu::get_menu_items();
         if ($allMenuItems) {
             foreach ($allMenuItems as $code => $menuItem) {
                         // exclude all items which have a controller to perform permission
@@ -286,7 +286,7 @@ public static function get_viewable_menu_items($member = null)
      */
     public static function remove_menu_item($code)
     {
-        self::$menu_item_changes[] = ['type' => 'remove', 'code' => $code];
+        CMSMenu::$menu_item_changes[] = ['type' => 'remove', 'code' => $code];
     }
 
     /**
@@ -296,8 +296,8 @@ public static function remove_menu_item($code)
      */
     public static function remove_menu_class($className)
     {
-        $code = self::get_menu_code($className);
-        self::remove_menu_item($code);
+        $code = CMSMenu::get_menu_code($className);
+        CMSMenu::remove_menu_item($code);
     }
 
     /**
@@ -305,8 +305,8 @@ public static function remove_menu_class($className)
      */
     public static function clear_menu()
     {
-        self::$menu_item_changes = [];
-        self::$menu_is_cleared = true;
+        CMSMenu::$menu_item_changes = [];
+        CMSMenu::$menu_is_cleared = true;
     }
 
     /**
@@ -341,7 +341,7 @@ public static function replace_menu_item(
             $item->setAttributes($attributes);
         }
 
-        self::$menu_item_changes[] = [
+        CMSMenu::$menu_item_changes[] = [
             'type' => 'add',
             'code' => $code,
             'item' => $item,
@@ -356,7 +356,7 @@ public static function replace_menu_item(
      */
     protected static function add_menu_item_obj($code, $cmsMenuItem)
     {
-        self::$menu_item_changes[] = [
+        CMSMenu::$menu_item_changes[] = [
             'type' => 'add',
             'code' => $code,
             'item' => $cmsMenuItem,
@@ -374,7 +374,7 @@ protected static function add_menu_item_obj($code, $cmsMenuItem)
      * @param string $sort Name of config on which to sort. Can be 'menu_priority' or 'url_priority'
      * @return array Valid, unique subclasses
      */
-    public static function get_cms_classes($root = null, $recursive = true, $sort = self::MENU_PRIORITY)
+    public static function get_cms_classes($root = null, $recursive = true, $sort = CMSMenu::MENU_PRIORITY)
     {
         if (!$root) {
             $root = LeftAndMain::class;
@@ -415,7 +415,7 @@ public static function get_cms_classes($root = null, $recursive = true, $sort =
      */
     public function getIterator(): Traversable
     {
-        return new ArrayIterator(self::get_menu_items());
+        return new ArrayIterator(CMSMenu::get_menu_items());
     }
 
     /**
@@ -423,7 +423,7 @@ public function getIterator(): Traversable
      */
     public function provideI18nEntities()
     {
-        $cmsClasses = self::get_cms_classes();
+        $cmsClasses = CMSMenu::get_cms_classes();
         $entities = [];
         foreach ($cmsClasses as $cmsClass) {
             $defaultTitle = LeftAndMain::menu_title($cmsClass, false);
diff --git a/code/LeftAndMain.php b/code/LeftAndMain.php
index 0af467cf4..edefe9ac9 100644
--- a/code/LeftAndMain.php
+++ b/code/LeftAndMain.php
@@ -597,7 +597,7 @@ public static function getRequiredPermissions()
     {
         $class = get_called_class();
         // If the user is accessing LeftAndMain directly, only generic permissions are required.
-        if ($class === self::class) {
+        if ($class === LeftAndMain::class) {
             return 'CMS_ACCESS';
         }
         $code = Config::inst()->get($class, 'required_permission_codes');
@@ -814,7 +814,7 @@ public function afterHandleRequest()
             $errorCode = $this->response->getStatusCode();
             $errorType = $this->response->getStatusDescription();
             $defaultMessage = _t(
-                self::class . '.ErrorMessage',
+                LeftAndMain::class . '.ErrorMessage',
                 'Sorry, it seems there was a {errorcode} error.',
                 ['errorcode' => $errorCode]
             );
@@ -825,7 +825,7 @@ public function afterHandleRequest()
                     'ErrorType' => $errorType,
                     'Message' => DBField::create_field(
                         'HTMLFragment',
-                        _t(self::class . '.ErrorMessage' . $errorCode, $defaultMessage)
+                        _t(LeftAndMain::class . '.ErrorMessage' . $errorCode, $defaultMessage)
                     ),
                 ]),
             ]), $errorCode, $errorType);
@@ -2067,7 +2067,7 @@ public function getHttpErrorMessage(): string
      * Called by {@link LeftAndMainErrorExtension}
      * @internal
      */
-    public function setHttpErrorMessage(string $message): self
+    public function setHttpErrorMessage(string $message): LeftAndMain
     {
         $this->httpErrorMessage = $message;
         return $this;
diff --git a/code/ModelAdmin.php b/code/ModelAdmin.php
index 5af2b9c1c..228d8c293 100644
--- a/code/ModelAdmin.php
+++ b/code/ModelAdmin.php
@@ -141,7 +141,7 @@ abstract class ModelAdmin extends LeftAndMain
      *
      * Sets the `modelClass` field which determines which of the {@link DataObject} objects will have visible data. This
      * is determined by the URL (with the first slug being the name of the DataObject class to represent. If this class
-     * is loaded without any URL, we pick the first DataObject from the list of {@link self::$managed_models}.
+     * is loaded without any URL, we pick the first DataObject from the list of {@link ModelAdmin::$managed_models}.
      */
     protected function init()
     {
@@ -247,7 +247,7 @@ public function getCMSEditLinkForManagedDataObject(DataObject $obj): string
     /**
      * Produces an edit form that includes a default {@link \SilverStripe\Forms\GridField\GridField} for the currently
      * active {@link \SilverStripe\ORM\DataObject}. The GridField will show data from the currently active `modelClass`
-     * only (see {@link self::init()}).
+     * only (see {@link ModelAdmin::init()}).
      *
      * @param int|null $id
      * @param \SilverStripe\Forms\FieldList $fields
@@ -534,8 +534,8 @@ public function isManagedModel(string $modelClassOrModelTab): bool
     }
 
     /**
-     * Returns all importers defined in {@link self::$model_importers}.
-     * If none are defined, we fall back to {@link self::managed_models}
+     * Returns all importers defined in {@link ModelAdmin::$model_importers}.
+     * If none are defined, we fall back to {@link ModelAdmin::managed_models}
      * with a default {@link CsvBulkLoader} class. In this case the column names of the first row
      * in the CSV file are assumed to have direct mappings to properties on the object.
      *
@@ -645,7 +645,7 @@ public function ImportForm()
 
     /**
      * Imports the submitted CSV file based on specifications given in
-     * {@link self::model_importers}.
+     * {@link ModelAdmin::model_importers}.
      * Redirects back with a success/failure message.
      */
     public function import(array $data, Form $form): HTTPResponse
diff --git a/tests/php/Navigator/SilverStripeNavigatorTest_TestItem.php b/tests/php/Navigator/SilverStripeNavigatorTest_TestItem.php
index ba788b8df..d1a523b33 100644
--- a/tests/php/Navigator/SilverStripeNavigatorTest_TestItem.php
+++ b/tests/php/Navigator/SilverStripeNavigatorTest_TestItem.php
@@ -9,7 +9,7 @@ class SilverStripeNavigatorTest_TestItem extends SilverStripeNavigatorItem imple
 {
     public function getTitle()
     {
-        return self::class;
+        return SilverStripeNavigatorTest_TestItem::class;
     }
 
     public function getHTML()