diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3fef572..35fbbf8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+CategoriesPage 1.3 - 2023.10.15
+===========================================================
+* Require Dotclear 2.28
+* Require PHP 8.1
+* Upgrade to Dotclear 2.28
+
 CategoriesPage 1.2 - 2023.08.06
 ===========================================================
 * Require Dotclear 2.27
diff --git a/README.md b/README.md
index 39ab250..c3dc324 100644
--- a/README.md
+++ b/README.md
@@ -1,25 +1,22 @@
 # README
 
-[![Release](https://img.shields.io/badge/release-1.2-a2cbe9.svg)](https://git.dotclear.watch/JcDenis/CategoriesPage/releases)
-[![Date](https://img.shields.io/badge/date-2023.08.06-c44d58.svg)](https://git.dotclear.watch/JcDenis/CategoriesPage/releases)
-[![Dotclear](https://img.shields.io/badge/dotclear-v2.27-137bbb.svg)](https://fr.dotclear.org/download)
+[![Release](https://img.shields.io/badge/release-1.3-a2cbe9.svg)](https://git.dotclear.watch/JcDenis/CategoriesPage/releases)
+![Date](https://img.shields.io/badge/date-2023.10.15-c44d58.svg)
+[![Dotclear](https://img.shields.io/badge/dotclear-v2.28-137bbb.svg)](https://fr.dotclear.org/download)
 [![Dotaddict](https://img.shields.io/badge/dotaddict-official-9ac123.svg)](https://plugins.dotaddict.org/dc2/details/CategoriesPage)
-[![License](https://img.shields.io/github/license/JcDenis/CategoriesPage)](https://git.dotclear.watch/JcDenis/CategoriesPage/blob/master/LICENSE)
+[![License](https://img.shields.io/badge/license-GPL--2.0-ececec.svg)](https://git.dotclear.watch/JcDenis/CategoriesPage/src/branch/master/LICENSE)
 
-## WHAT IS CATEGORIESPAGE ?
+## ABOUT
 
-_CategoriesPage_ is a plugin for the open-source 
-web publishing software called Dotclear.
+_CategoriesPage_ is a plugin for the open-source web publishing software called [Dotclear](https://www.dotclear.org).
 
-Add a public page to list blog categories.
-A widget is also available.
+> Add a public page to list blog categories. A widget is also available.
 
 ## REQUIREMENTS
 
- _CategoriesPage_ requires: 
-
-  * admin permissions
-  * Dotclear 2.27
+* Dotclear 2.28
+* PHP 8.1
+* admin permissions
 
 ## USAGE
 
@@ -31,14 +28,15 @@ default templates are on plugin directory CategoriesPage/default-templates/
 
 ## LINKS
 
- * License : [GNU GPL v2](https://www.gnu.org/licenses/old-licenses/lgpl-2.0.html)
- * Source & contribution : [Gitea Page](https://git.dotclear.watch/JcDenis/CategoriesPage) or [GitHub Page](https://github.com/JcDenis/CategoriesPage)
- * Packages & details : [Gitea Page](https://git.dotclear.watch/JcDenis/CategoriesPage/releases) or [Dotaddict Page](https://plugins.dotaddict.org/dc2/details/CategoriesPage)
+* [License](https://git.dotclear.watch/JcDenis/CategoriesPage/src/branch/master/LICENSE)
+* [Packages & details](https://git.dotclear.watch/JcDenis/CategoriesPage/releases) (or on [Dotaddict](https://plugins.dotaddict.org/dc2/details/CategoriesPage))
+* [Sources & contributions](https://git.dotclear.watch/JcDenis/CategoriesPage) (or on [GitHub](https://github.com/JcDenis/CategoriesPage))
+* [Issues & security](https://git.dotclear.watch/JcDenis/CategoriesPage/issues) (or on [GitHub](https://github.com/JcDenis/CategoriesPage/issues))
 
 ## CONTRIBUTORS
 
- * Pierre Van Glabeke
- * Bernard Le Roux
- * Jean-Christian Denis
+* Pierre Van Glabeke (author)
+* Bernard Le Roux
+* Jean-Christian Denis (latest)
 
- You are welcome to contribute to this code.
\ No newline at end of file
+You are welcome to contribute to this code.
diff --git a/_define.php b/_define.php
index e81414f..d152338 100644
--- a/_define.php
+++ b/_define.php
@@ -1,33 +1,31 @@
 <?php
 /**
- * @brief CategoriesPage, a plugin for Dotclear 2
+ * @file
+ * @brief       The plugin CategoriesPage definition
+ * @ingroup     CategoriesPage
  *
- * @package Dotclear
- * @subpackage Plugin
+ * @defgroup    CategoriesPage Plugin CategoriesPage.
  *
- * @author Pierre Van Glabeke, Bernard Le Roux and Contributors
+ * Add a public page for categories list.
  *
- * @copyright Jean-Christian Denis
- * @copyright GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
+ * @author      Pierre Van Glabeke (author)
+ * @author      Jean-Christian Denis (latest)
+ * @copyright   GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
  */
-if (!defined('DC_RC_PATH')) {
-    return null;
-}
+declare(strict_types=1);
 
 $this->registerModule(
     'Categories Page',
     'Add a public page for categories list',
     'Pierre Van Glabeke, Bernard Le Roux and Contributors',
-    '1.2',
+    '1.3',
     [
-        'requires'    => [['core', '2.27']],
-        'permissions' => dcCore::app()->auth->makePermissions([
-            dcAuth::PERMISSION_ADMIN,
-        ]),
-        'type'       => 'plugin',
-        'support'    => 'https://git.dotclear.watch/JcDenis/' . basename(__DIR__) . '/issues',
-        'details'    => 'https://git.dotclear.watch/JcDenis/' . basename(__DIR__) . '/src/branch/master/README.md',
-        'repository' => 'https://git.dotclear.watch/JcDenis/' . basename(__DIR__) . '/raw/branch/master/dcstore.xml',
+        'requires'    => [['core', '2.28']],
+        'permissions' => 'My',
+        'type'        => 'plugin',
+        'support'     => 'https://git.dotclear.watch/JcDenis/' . basename(__DIR__) . '/issues',
+        'details'     => 'https://git.dotclear.watch/JcDenis/' . basename(__DIR__) . '/src/branch/master/README.md',
+        'repository'  => 'https://git.dotclear.watch/JcDenis/' . basename(__DIR__) . '/raw/branch/master/dcstore.xml',
 
     ]
 );
diff --git a/dcstore.xml b/dcstore.xml
index 0ef8a51..e26a740 100644
--- a/dcstore.xml
+++ b/dcstore.xml
@@ -2,11 +2,11 @@
 <modules xmlns:da="http://dotaddict.org/da/">
   <module id="CategoriesPage">
     <name>Categories Page</name>
-    <version>1.2</version>
+    <version>1.3</version>
     <author>Pierre Van Glabeke, Bernard Le Roux and Contributors</author>
     <desc>Add a public page for categories list</desc>
-    <file>https://git.dotclear.watch/JcDenis/CategoriesPage/releases/download/v1.2/plugin-CategoriesPage.zip</file>
-    <da:dcmin>2.27</da:dcmin>
+    <file>https://git.dotclear.watch/JcDenis/CategoriesPage/releases/download/v1.3/plugin-CategoriesPage.zip</file>
+    <da:dcmin>2.28</da:dcmin>
     <da:details>https://git.dotclear.watch/JcDenis/CategoriesPage/src/branch/master/README.md</da:details>
     <da:support>https://git.dotclear.watch/JcDenis/CategoriesPage/issues</da:support>
   </module>
diff --git a/src/Backend.php b/src/Backend.php
index 8de956d..1bc6475 100644
--- a/src/Backend.php
+++ b/src/Backend.php
@@ -1,22 +1,20 @@
 <?php
-/**
- * @brief CategoriesPage, a plugin for Dotclear 2
- *
- * @package Dotclear
- * @subpackage Plugin
- *
- * @author Pierre Van Glabeke, Bernard Le Roux and Contributors
- *
- * @copyright Jean-Christian Denis
- * @copyright GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
- */
+
 declare(strict_types=1);
 
 namespace Dotclear\Plugin\CategoriesPage;
 
-use dcCore;
+use Dotclear\App;
 use Dotclear\Core\Process;
 
+/**
+ * @brief       CategoriesPage backend class.
+ * @ingroup     CategoriesPage
+ *
+ * @author      Pierre Van Glabeke (author)
+ * @author      Jean-Christian Denis (latest)
+ * @copyright   GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
+ */
 class Backend extends Process
 {
     public static function init(): bool
@@ -30,9 +28,7 @@ class Backend extends Process
             return false;
         }
 
-        dcCore::app()->addBehaviors([
-            'initWidgets' => [Widgets::class, 'initWidgets'],
-        ]);
+        App::behavior()->addBehavior('initWidgets', Widgets::initWidgets(...));
 
         return true;
     }
diff --git a/src/Frontend.php b/src/Frontend.php
index 172d673..dd32f5b 100644
--- a/src/Frontend.php
+++ b/src/Frontend.php
@@ -1,23 +1,21 @@
 <?php
-/**
- * @brief CategoriesPage, a plugin for Dotclear 2
- *
- * @package Dotclear
- * @subpackage Plugin
- *
- * @author Pierre Van Glabeke, Bernard Le Roux and Contributors
- *
- * @copyright Jean-Christian Denis
- * @copyright GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
- */
+
 declare(strict_types=1);
 
 namespace Dotclear\Plugin\CategoriesPage;
 
 use ArrayObject;
-use dcCore;
+use Dotclear\App;
 use Dotclear\Core\Process;
 
+/**
+ * @brief       CategoriesPage frontend class.
+ * @ingroup     CategoriesPage
+ *
+ * @author      Pierre Van Glabeke (author)
+ * @author      Jean-Christian Denis (latest)
+ * @copyright   GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
+ */
 class Frontend extends Process
 {
     public static function init(): bool
@@ -31,19 +29,18 @@ class Frontend extends Process
             return false;
         }
 
-        dcCore::app()->addBehaviors([
+        App::behavior()->addBehaviors([
             // template path
             'publicBeforeDocumentV2' => function (): void {
-                // nullsafe PHP < 8.0
-                if (is_null(dcCore::app()->blog)) {
+                if (!App::blog()->isDefined()) {
                     return ;
                 }
 
-                $tplset = dcCore::app()->themes->moduleInfo(dcCore::app()->blog->settings->get('system')->get('theme'), 'tplset');
+                $tplset = App::themes()->moduleInfo(App::blog()->settings()->get('system')->get('theme'), 'tplset');
                 if (!empty($tplset) && is_dir(implode(DIRECTORY_SEPARATOR, [My::path(), 'default-templates', $tplset]))) {
-                    dcCore::app()->tpl->setPath(dcCore::app()->tpl->getPath(), implode(DIRECTORY_SEPARATOR, [My::path(), 'default-templates', $tplset]));
+                    App::frontend()->template()->setPath(App::frontend()->template()->getPath(), implode(DIRECTORY_SEPARATOR, [My::path(), 'default-templates', $tplset]));
                 } else {
-                    dcCore::app()->tpl->setPath(dcCore::app()->tpl->getPath(), implode(DIRECTORY_SEPARATOR, [My::path(), 'default-templates', DC_DEFAULT_TPLSET]));
+                    App::frontend()->template()->setPath(App::frontend()->template()->getPath(), implode(DIRECTORY_SEPARATOR, [My::path(), 'default-templates', App::config()->defaultTplset()]));
                 }
             },
             // breacrumb addon
@@ -51,15 +48,15 @@ class Frontend extends Process
                 return $context == 'categories' ? My::name() : '';
             },
             // widget
-            'initWidgets' => [Widgets::class, 'initWidgets'],
+            'initWidgets' => Widgets::initWidgets(...),
         ]);
 
         // tpl values
-        dcCore::app()->tpl->addValue('CategoryCount', function (ArrayObject $attr): string {
-            return '<?php echo ' . sprintf(dcCore::app()->tpl->getFilters($attr), 'dcCore::app()->ctx->categories->nb_post') . '; ?>';
+        App::frontend()->template()->addValue('CategoryCount', function (ArrayObject $attr): string {
+            return '<?php echo ' . sprintf(App::frontend()->template()->getFilters($attr), 'App::frontend()->context()->categories->nb_post') . '; ?>';
         });
-        dcCore::app()->tpl->addValue('CategoriesURL', function (ArrayObject $attr): string {
-            return '<?php echo ' . sprintf(dcCore::app()->tpl->getFilters($attr), 'dcCore::app()->blog->url.dcCore::app()->url->getBase("categories")') . '; ?>';
+        App::frontend()->template()->addValue('CategoriesURL', function (ArrayObject $attr): string {
+            return '<?php echo ' . sprintf(App::frontend()->template()->getFilters($attr), 'App::blog()->url().App::url()->getBase("categories")') . '; ?>';
         });
 
         return true;
diff --git a/src/My.php b/src/My.php
index b01b31c..e207c06 100644
--- a/src/My.php
+++ b/src/My.php
@@ -1,15 +1,5 @@
 <?php
-/**
- * @brief CategoriesPage, a plugin for Dotclear 2
- *
- * @package Dotclear
- * @subpackage Plugin
- *
- * @author Pierre Van Glabeke, Bernard Le Roux and Contributors
- *
- * @copyright Jean-Christian Denis
- * @copyright GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
- */
+
 declare(strict_types=1);
 
 namespace Dotclear\Plugin\CategoriesPage;
@@ -17,8 +7,14 @@ namespace Dotclear\Plugin\CategoriesPage;
 use Dotclear\Module\MyPlugin;
 
 /**
- * This module definitions.
+ * @brief       CategoriesPage My helper.
+ * @ingroup     CategoriesPage
+ *
+ * @author      Pierre Van Glabeke (author)
+ * @author      Jean-Christian Denis (latest)
+ * @copyright   GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
  */
 class My extends MyPlugin
 {
+    // Use default permissions
 }
diff --git a/src/Prepend.php b/src/Prepend.php
index 7d781a9..0ab530a 100644
--- a/src/Prepend.php
+++ b/src/Prepend.php
@@ -1,22 +1,20 @@
 <?php
-/**
- * @brief CategoriesPage, a plugin for Dotclear 2
- *
- * @package Dotclear
- * @subpackage Plugin
- *
- * @author Pierre Van Glabeke, Bernard Le Roux and Contributors
- *
- * @copyright Jean-Christian Denis
- * @copyright GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
- */
+
 declare(strict_types=1);
 
 namespace Dotclear\Plugin\CategoriesPage;
 
-use dcCore;
+use Dotclear\App;
 use Dotclear\Core\Process;
 
+/**
+ * @brief       CategoriesPage prepend class.
+ * @ingroup     CategoriesPage
+ *
+ * @author      Pierre Van Glabeke (author)
+ * @author      Jean-Christian Denis (latest)
+ * @copyright   GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
+ */
 class Prepend extends Process
 {
     public static function init(): bool
@@ -30,11 +28,11 @@ class Prepend extends Process
             return false;
         }
 
-        dcCore::app()->url->register(
+        App::url()->register(
             'categories',
             'categories',
             '^categories$',
-            [UrlHandler::class, 'categories']
+            UrlHandler::categories(...)
         );
 
         return true;
diff --git a/src/UrlHandler.php b/src/UrlHandler.php
index 8d94ae3..4136cf8 100644
--- a/src/UrlHandler.php
+++ b/src/UrlHandler.php
@@ -1,22 +1,20 @@
 <?php
-/**
- * @brief CategoriesPage, a plugin for Dotclear 2
- *
- * @package Dotclear
- * @subpackage Plugin
- *
- * @author Pierre Van Glabeke, Bernard Le Roux and Contributors
- *
- * @copyright Jean-Christian Denis
- * @copyright GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
- */
+
 declare(strict_types=1);
 
 namespace Dotclear\Plugin\CategoriesPage;
 
-use dcUrlHandlers;
+use Dotclear\Core\Frontend\Url;
 
-class UrlHandler extends dcUrlHandlers
+/**
+ * @brief       CategoriesPage frontend URL handler class.
+ * @ingroup     CategoriesPage
+ *
+ * @author      Pierre Van Glabeke (author)
+ * @author      Jean-Christian Denis (latest)
+ * @copyright   GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
+ */
+class UrlHandler extends Url
 {
     public static function categories(?string $args): void
     {
diff --git a/src/Widgets.php b/src/Widgets.php
index b562ca9..d8a9675 100644
--- a/src/Widgets.php
+++ b/src/Widgets.php
@@ -1,24 +1,22 @@
 <?php
-/**
- * @brief CategoriesPage, a plugin for Dotclear 2
- *
- * @package Dotclear
- * @subpackage Plugin
- *
- * @author Pierre Van Glabeke, Bernard Le Roux and Contributors
- *
- * @copyright Jean-Christian Denis
- * @copyright GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
- */
+
 declare(strict_types=1);
 
 namespace Dotclear\Plugin\CategoriesPage;
 
-use dcCore;
+use Dotclear\App;
 use Dotclear\Helper\Html\Html;
 use Dotclear\Plugin\widgets\WidgetsStack;
 use Dotclear\Plugin\widgets\WidgetsElement;
 
+/**
+ * @brief       CategoriesPage widgets class.
+ * @ingroup     CategoriesPage
+ *
+ * @author      Pierre Van Glabeke (author)
+ * @author      Jean-Christian Denis (latest)
+ * @copyright   GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
+ */
 class Widgets
 {
     public static function initWidgets(WidgetsStack $w): void
@@ -27,7 +25,7 @@ class Widgets
             ->create(
                 My::id(),
                 My::name(),
-                [self::class, 'parseWidget'],
+                self::parseWidget(...),
                 null,
                 __('Link to categories')
             )
@@ -40,12 +38,10 @@ class Widgets
 
     public static function parseWidget(WidgetsElement $w): string
     {
-        if ($w->offline || !$w->checkHomeOnly(dcCore::app()->url->type)) {
-            return '';
-        }
-
-        // nullsafe PHP < 8.0
-        if (is_null(dcCore::app()->blog)) {
+        if ($w->offline
+            || !$w->checkHomeOnly(App::url()->type)
+            || !App::blog()->isDefined()
+        ) {
             return '';
         }
 
@@ -54,7 +50,7 @@ class Widgets
             My::id() . ' ' . $w->class,
             '',
             ($w->title ? $w->renderTitle(Html::escapeHTML($w->title)) : '') .
-            '<p><a href="' . dcCore::app()->blog->url . dcCore::app()->url->getBase('categories') . '">' .
+            '<p><a href="' . App::blog()->url() . App::url()->getBase('categories') . '">' .
             ($w->link_title ? Html::escapeHTML($w->link_title) : __('All categories')) .
             '</a></p>'
         );