diff --git a/bl-kernel/abstract/dblist.class.php b/bl-kernel/abstract/dblist.class.php
index 42d8a8b5..55610f22 100644
--- a/bl-kernel/abstract/dblist.class.php
+++ b/bl-kernel/abstract/dblist.class.php
@@ -99,6 +99,11 @@ class dbList extends dbJSON
 		return $key;
 	}
 
+	/*	Delete an item from the dblist === Bludit v4
+
+		@key			string			Key of the item to be deleted
+		@returns		boolean			Returns TRUE if the database was successfully saved, FALSE otherwise
+	*/
 	public function remove($key)
 	{
 		if (!isset($this->db[$key])) {
@@ -184,16 +189,21 @@ class dbList extends dbJSON
 		return false;
 	}
 
-	// Returns an array with a portion of the database filtered by key
-	// Returns array( 'key'=>'', 'name'=>'', 'template'=>'', 'description'=>'', list'=>array() )
+	/*	Returns an array with a portion of the database filtered by key === Bludit v4
+
+		@key			string			The item key
+		@returns		array/bool		Returns the following structure array('key'=>'', 'name'=>'', 'template'=>'', 'description'=>'', list'=>array()), FALSE if the key doesn't exist
+	*/
 	public function getMap($key)
 	{
-		if (isset($this->db[$key])) {
-			$tmp = $this->db[$key];
-			$tmp['key'] = $key;
-			return $tmp;
+		if (!$this->exists($key)) {
+			Log::set(__METHOD__.LOG_SEP.'The item doesn\'t exist. Key: '.$key);
+			return false;
 		}
-		return false;
+
+		$tmp = $this->db[$key];
+		$tmp['key'] = $key;
+		return $tmp;
 	}
 
 }
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/about.php b/bl-kernel/admin/controllers/about.php
index a27002e5..34b62b19 100644
--- a/bl-kernel/admin/controllers/about.php
+++ b/bl-kernel/admin/controllers/about.php
@@ -1,4 +1,16 @@
 <?php defined('BLUDIT') or die('Bludit CMS.');
 
-// Title of the page
+// ============================================================================
+// Authorization
+// ============================================================================
+
+// ============================================================================
+// Functions
+// ============================================================================
+
+// ============================================================================
+// Main
+// ============================================================================
+
+// HTML <title>
 $layout['title'] = $L->g('About') . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/add-category.php b/bl-kernel/admin/controllers/add-category.php
index 5284f90c..6529ab51 100644
--- a/bl-kernel/admin/controllers/add-category.php
+++ b/bl-kernel/admin/controllers/add-category.php
@@ -15,4 +15,4 @@ checkRole(array('admin'));
 // ============================================================================
 
 // HTML <title>
-$layout['title'] .= ' - '.$L->g('New category');
\ No newline at end of file
+$layout['title'] = $L->g('New category') . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/add-user.php b/bl-kernel/admin/controllers/add-user.php
index 68659d3a..3783450a 100644
--- a/bl-kernel/admin/controllers/add-user.php
+++ b/bl-kernel/admin/controllers/add-user.php
@@ -15,4 +15,4 @@ checkRole(array('admin'));
 // ============================================================================
 
 // HTML <title>
-$layout['title'] .= ' - '.$L->g('New user');
\ No newline at end of file
+$layout['title'] = $L->g('New user') . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/categories.php b/bl-kernel/admin/controllers/categories.php
index 3a22161b..baf4a0d0 100644
--- a/bl-kernel/admin/controllers/categories.php
+++ b/bl-kernel/admin/controllers/categories.php
@@ -1,7 +1,7 @@
 <?php defined('BLUDIT') or die('Bludit CMS.');
 
 // ============================================================================
-// Check role
+// Authorization
 // ============================================================================
 
 checkRole(array('admin'));
@@ -11,16 +11,8 @@ checkRole(array('admin'));
 // ============================================================================
 
 // ============================================================================
-// Main before POST
+// Main
 // ============================================================================
 
-// ============================================================================
-// POST Method
-// ============================================================================
-
-// ============================================================================
-// Main after POST
-// ============================================================================
-
-// Title of the page
-$layout['title'] .= ' - '.$L->g('Categories');
\ No newline at end of file
+// HTML <title>
+$layout['title'] = $L->g('Categories') . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/edit-category.php b/bl-kernel/admin/controllers/edit-category.php
index 9df8f48c..ac4fa37a 100644
--- a/bl-kernel/admin/controllers/edit-category.php
+++ b/bl-kernel/admin/controllers/edit-category.php
@@ -1,7 +1,7 @@
 <?php defined('BLUDIT') or die('Bludit CMS.');
 
 // ============================================================================
-// Check role
+// Authorization
 // ============================================================================
 
 checkRole(array('admin'));
@@ -11,26 +11,9 @@ checkRole(array('admin'));
 // ============================================================================
 
 // ============================================================================
-// Main before POST
+// Main
 // ============================================================================
 
-// ============================================================================
-// POST Method
-// ============================================================================
-
-if ($_SERVER['REQUEST_METHOD'] == 'POST') {
-	if ($_POST['action']=='delete') {
-		deleteCategory($_POST);
-	} elseif ($_POST['action']=='edit') {
-		editCategory($_POST);
-	}
-
-	Redirect::page('categories');
-}
-
-// ============================================================================
-// Main after POST
-// ============================================================================
 $categoryKey = $layout['parameters'];
 
 if (!$categories->exists($categoryKey)) {
@@ -40,5 +23,5 @@ if (!$categories->exists($categoryKey)) {
 
 $categoryMap = $categories->getMap($categoryKey);
 
-// Title of the page
-$layout['title'] .= ' - '.$L->g('Edit Category').' [ '.$categoryMap['name'] . ' ] ';
\ No newline at end of file
+// HTML <title>
+$layout['title'] = $L->g('Edit Category') . ' [ ' . $categoryMap['name'] . ' ] ' . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/edit-user.php b/bl-kernel/admin/controllers/edit-user.php
index 7caa38e4..bc6b0304 100644
--- a/bl-kernel/admin/controllers/edit-user.php
+++ b/bl-kernel/admin/controllers/edit-user.php
@@ -1,46 +1,15 @@
 <?php defined('BLUDIT') or die('Bludit CMS.');
 
+// ============================================================================
+// Authorization
+// ============================================================================
+
 // ============================================================================
 // Functions
 // ============================================================================
 
 // ============================================================================
-// Main before POST
-// ============================================================================
-
-// ============================================================================
-// POST Method
-// ============================================================================
-
-if ($_SERVER['REQUEST_METHOD'] == 'POST') {
-	// Prevent non-administrators to change other users
-	if ($login->role()!=='admin') {
-		$_POST['username'] = $login->username();
-		unset($_POST['role']);
-	}
-
-	if (isset($_POST['deleteUserAndDeleteContent']) && ($login->role()==='admin')) {
-		$_POST['deleteContent'] = true;
-		deleteUser($_POST);
-	} elseif (isset($_POST['deleteUserAndKeepContent']) && ($login->role()==='admin')) {
-		$_POST['deleteContent'] = false;
-		deleteUser($_POST);
-	} elseif (isset($_POST['disableUser']) && ($login->role()==='admin')) {
-		disableUser(array('username'=>$_POST['username']));
-	} else {
-		editUser($_POST);
-	}
-
-	Alert::set($L->g('The changes have been saved'));
-
-	if ($login->role()==='admin') {
-		Redirect::page('users');
-	}
-	Redirect::page('edit-user/'.$login->username());
-}
-
-// ============================================================================
-// Main after POST
+// Main
 // ============================================================================
 
 $username = $layout['parameters'];
@@ -56,5 +25,5 @@ try {
 	Redirect::page('users');
 }
 
-// Title of the page
-$layout['title'] = $L->g('Edit user').' - '.$layout['title'];
\ No newline at end of file
+// HTML <title>
+$layout['title'] = $L->g('Edit user') . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/plugins.php b/bl-kernel/admin/controllers/plugins.php
index 074f555a..8c5f62df 100644
--- a/bl-kernel/admin/controllers/plugins.php
+++ b/bl-kernel/admin/controllers/plugins.php
@@ -1,7 +1,7 @@
 <?php defined('BLUDIT') or die('Bludit CMS.');
 
 // ============================================================================
-// Check role
+// Authorization
 // ============================================================================
 
 checkRole(array('admin'));
@@ -11,16 +11,8 @@ checkRole(array('admin'));
 // ============================================================================
 
 // ============================================================================
-// Main before POST
+// Main
 // ============================================================================
 
-// ============================================================================
-// POST Method
-// ============================================================================
-
-// ============================================================================
-// Main after POST
-// ============================================================================
-
-// Title of the page
-$layout['title'] .= ' - '.$L->g('Plugins');
\ No newline at end of file
+// HTML <title>
+$layout['title'] = $L->g('Plugins') . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/themes.php b/bl-kernel/admin/controllers/themes.php
index 43e3dbf3..8b503f06 100644
--- a/bl-kernel/admin/controllers/themes.php
+++ b/bl-kernel/admin/controllers/themes.php
@@ -21,4 +21,4 @@ checkRole(array('admin'));
 $themes = buildThemes();
 
 // Title of the page
-$layout['title'] .= ' - '.$L->g('Themes');
\ No newline at end of file
+$layout['title'] = $L->g('Themes') . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/controllers/users.php b/bl-kernel/admin/controllers/users.php
index a9a00232..7f1f4ca1 100644
--- a/bl-kernel/admin/controllers/users.php
+++ b/bl-kernel/admin/controllers/users.php
@@ -1,7 +1,7 @@
 <?php defined('BLUDIT') or die('Bludit CMS.');
 
 // ============================================================================
-// Check role
+// Authorization
 // ============================================================================
 
 checkRole(array('admin'));
@@ -11,21 +11,8 @@ checkRole(array('admin'));
 // ============================================================================
 
 // ============================================================================
-// Main after POST
+// Main
 // ============================================================================
 
-// ============================================================================
-// POST Method
-// ============================================================================
-
-if( $_SERVER['REQUEST_METHOD'] == 'POST' )
-{
-	$site->set($_POST);
-}
-
-// ============================================================================
-// Main after POST
-// ============================================================================
-
-// Title of the page
-$layout['title'] .= ' - '.$L->g('Users');
\ No newline at end of file
+// HTML <title>
+$layout['title'] = $L->g('Users') . ' - ' . $layout['title'];
\ No newline at end of file
diff --git a/bl-kernel/admin/themes/booty/html/alerts.php b/bl-kernel/admin/themes/booty/html/alerts.php
index 7de14ba1..42cc2dad 100644
--- a/bl-kernel/admin/themes/booty/html/alerts.php
+++ b/bl-kernel/admin/themes/booty/html/alerts.php
@@ -1,8 +1,7 @@
 <div aria-live="polite" aria-atomic="true" class="position-relative">
-	<div class="toast-container position-absolute top-0 end-0 p-3" style="z-index:1050;">
-		<div id="alert" class="toast d-flex align-items-center text-white border-0" role="alert" aria-live="assertive" aria-atomic="true">
-			<div class="toast-body">Hello, I'm a Bludit alert!</div>
-			<button type="button" class="btn-close btn-close-white ms-auto me-2" data-bs-dismiss="toast" aria-label="Close"></button>
+	<div class="toast-container position-absolute start-50 translate-middle-x mt-3" style="z-index:1050;">
+		<div id="alert" class="toast text-center text-white border-0 p-3" role="alert" aria-live="assertive" aria-atomic="true">
+			Hello, I'm a Bludit alert!
 		</div>
 	</div>
 </div>
@@ -10,7 +9,7 @@
 <script>
 function showAlert(text, background='primary') {
 	$('#alert').removeClass('bg-danger bg-warning bg-primary').addClass('bg-'+background);
-	$('#alert').children('.toast-body').html(text);
+	$('#alert').html(text);
 	$('#alert').toast('show');
 }
 
@@ -22,7 +21,7 @@ function showAlertWarning(text) {
 	showAlert(text, 'warning');
 }
 
-function showAlerInfo(text) {
+function showAlertInfo(text) {
 	showAlert(text, 'primary');
 }
 
diff --git a/bl-kernel/admin/themes/booty/html/sidebar.php b/bl-kernel/admin/themes/booty/html/sidebar.php
index c7407daf..ac778679 100644
--- a/bl-kernel/admin/themes/booty/html/sidebar.php
+++ b/bl-kernel/admin/themes/booty/html/sidebar.php
@@ -3,29 +3,29 @@
 
 	<li class="nav-item mb-3">
 		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'editor' ?>">
-			<i class="bi-plus-circle"></i>
+			<i class="bi bi-plus-circle"></i>
 			<?php $L->p('New content') ?>
 		</a>
 	</li>
 	<li class="nav-item">
 		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'dashboard' ?>">
-			<i class="bi-kanban"></i>
+			<i class="bi bi-kanban"></i>
 			<?php $L->p('Dashboard') ?>
 		</a>
 	</li>
 	<li class="nav-item">
 		<a class="nav-link" href="<?php echo DOMAIN_BASE ?>">
-			<i class="bi-house"></i>
+			<i class="bi bi-house"></i>
 			<?php $L->p('Website') ?>
 		</a>
 	</li>
 
 	<?php if (!checkRole(array('admin'),false)): ?>
 	<li class="nav-item">
-		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'content' ?>"><span class="bi-archive"></span><?php $L->p('Content') ?></a>
+		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'content' ?>"><span class="bi bi-archive"></span><?php $L->p('Content') ?></a>
 	</li>
 	<li class="nav-item">
-		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'edit-user/'.$login->username() ?>"><span class="bi-user"></span><?php $L->p('Profile') ?></a>
+		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'edit-user/'.$login->username() ?>"><span class="bi bi-user"></span><?php $L->p('Profile') ?></a>
 	</li>
 	<?php endif; ?>
 
@@ -36,19 +36,19 @@
 	</li>
 	<li class="nav-item">
 		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'content' ?>">
-			<i class="bi-folder"></i>
+			<i class="bi bi-folder"></i>
 			<?php $L->p('Content') ?>
 		</a>
 	</li>
 	<li class="nav-item">
 		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'categories' ?>">
-			<i class="bi-bookmark"></i>
+			<i class="bi bi-bookmark"></i>
 			<?php $L->p('Categories') ?>
 		</a>
 	</li>
 	<li class="nav-item">
 		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'users' ?>">
-			<i class="bi-people"></i>
+			<i class="bi bi-people"></i>
 			<?php $L->p('Users') ?>
 		</a>
 	</li>
@@ -57,16 +57,16 @@
 		<h4><?php $L->p('Settings') ?></h4>
 	</li>
 	<li class="nav-item">
-		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'settings' ?>"><?php $L->p('General') ?></a>
+		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'settings' ?>"><span class="bi bi-gear"></span><?php $L->p('General') ?></a>
 	</li>
 	<li class="nav-item">
-		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'plugins' ?>"><?php $L->p('Plugins') ?></a>
+		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'plugins' ?>"><span class="bi bi-node-plus"></span><?php $L->p('Plugins') ?></a>
 	</li>
 	<li class="nav-item">
-		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'themes' ?>"><?php $L->p('Themes') ?></a>
+		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'themes' ?>"><span class="bi bi-display"></span><?php $L->p('Themes') ?></a>
 	</li>
 	<li class="nav-item">
-		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'about' ?>"><?php $L->p('About') ?></a>
+		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'about' ?>"><span class="bi bi-info-circle"></span><?php $L->p('About') ?></a>
 	</li>
 
 	<?php endif; ?>
@@ -87,6 +87,6 @@
 	<?php endif; ?>
 
 	<li class="nav-item mt-5">
-		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'logout' ?>"><span class="bi-arrow-circle-right"></span><?php $L->p('Logout') ?></a>
+		<a class="nav-link" href="<?php echo HTML_PATH_ADMIN_ROOT.'logout' ?>"><span class="bi bi-door-closed"></span><?php $L->p('Logout') ?></a>
 	</li>
 </ul>
diff --git a/bl-kernel/admin/views/add-category.php b/bl-kernel/admin/views/add-category.php
index bbf81c27..14b44eaf 100644
--- a/bl-kernel/admin/views/add-category.php
+++ b/bl-kernel/admin/views/add-category.php
@@ -31,7 +31,7 @@ echo Bootstrap::formTextarea(array(
 			var name = $('#name').val();
 
 			if (name.length < 1) {
-				showAlertError("<?php $L->p('Please complete the name field.') ?>");
+				showAlertError("<?php $L->p('Complete all fields') ?>");
 				return false;
 			}
 
@@ -43,7 +43,6 @@ echo Bootstrap::formTextarea(array(
 				logs('Category created. Key: ' + key);
 				window.location.replace('<?php echo HTML_PATH_ADMIN_ROOT . 'categories' ?>');
 			});
-			showAlertInfo("Category created.");
 			return true;
 		});
 	});
diff --git a/bl-kernel/admin/views/add-user.php b/bl-kernel/admin/views/add-user.php
index fc805e4c..e6ae9d50 100644
--- a/bl-kernel/admin/views/add-user.php
+++ b/bl-kernel/admin/views/add-user.php
@@ -57,7 +57,7 @@ echo Bootstrap::formInputText(array(
 			var confirmPassword = $('#confirmPassword').val();
 
 			if (username.length < 1) {
-				showAlertError("<?php $L->p('Please complete the username field.') ?>");
+				showAlertError("<?php $L->p('Complete all fields') ?>");
 				return false;
 			}
 
@@ -81,8 +81,6 @@ echo Bootstrap::formInputText(array(
 				logs('User created. Username: ' + username);
 				window.location.replace(HTML_PATH_ADMIN_ROOT + 'users');
 			});
-
-			showAlertInfo("User created.");
 			return true;
 		});
 	});
diff --git a/bl-kernel/admin/views/edit-category.php b/bl-kernel/admin/views/edit-category.php
index da29d1f2..bbadb23c 100644
--- a/bl-kernel/admin/views/edit-category.php
+++ b/bl-kernel/admin/views/edit-category.php
@@ -1,92 +1,85 @@
 <?php defined('BLUDIT') or die('Bludit CMS.'); ?>
 
-<?php echo Bootstrap::formOpen(array('id'=>'jsform')); ?>
-
-<div class="align-middle">
-	<div class="float-end mt-1">
-		<button type="submit" class="btn btn-primary btn-sm" name="save"><?php $L->p('Save') ?></button>
-		<button type="button" class="btn btn-danger btn-sm" data-toggle="modal" data-target="#jsdeleteModal"><?php $L->p('Delete') ?></button>
-		<a class="btn btn-secondary btn-sm" href="<?php echo HTML_PATH_ADMIN_ROOT.'dashboard' ?>" role="button"><?php $L->p('Cancel') ?></a>
+<div class="d-flex align-items-center mb-4">
+	<h2 class="m-0"><i class="bi bi-bookmark"></i><?php $L->p('Edit category') ?></h2>
+	<div class="ms-auto">
+		<button id="btnSave" type="button" class="btn btn-primary btn-sm"><?php $L->p('Save') ?></button>
+		<button id="btnDelete" type="button" class="btn btn-danger btn-sm"><?php $L->p('Delete') ?></button>
+		<a id="btnCancel" class="btn btn-secondary btn-sm" href="<?php echo HTML_PATH_ADMIN_ROOT . 'categories' ?>" role="button"><?php $L->p('Cancel') ?></a>
 	</div>
-	<?php echo Bootstrap::pageTitle(array('title'=>$L->g('Edit Category'), 'icon'=>'cog')); ?>
 </div>
 
 <?php
-	// Token CSRF
-	echo Bootstrap::formInputHidden(array(
-		'name'=>'tokenCSRF',
-		'value'=>$security->getTokenCSRF()
-	));
+echo Bootstrap::formInputHidden(array(
+	'id' => 'key',
+	'name' => 'key',
+	'value' => $categoryMap['key']
+));
 
-	echo Bootstrap::formInputHidden(array(
-		'name'=>'action',
-		'value'=>'edit'
-	));
+echo Bootstrap::formInputText(array(
+	'id' => 'name',
+	'name' => 'name',
+	'label' => $L->g('Name'),
+	'value' => $categoryMap['name']
+));
 
-	echo Bootstrap::formInputHidden(array(
-		'name'=>'oldKey',
-		'value'=>$categoryMap['key']
-	));
+echo Bootstrap::formTextarea(array(
+	'name' => 'description',
+	'label' => $L->g('Description'),
+	'value' => isset($categoryMap['description']) ? $categoryMap['description'] : '',
+	'rows' => 3
+));
 
-	echo Bootstrap::formInputText(array(
-		'name'=>'name',
-		'label'=>$L->g('Name'),
-		'value'=>$categoryMap['name'],
-		'class'=>'',
-		'placeholder'=>'',
-		'tip'=>''
-	));
-
-	echo Bootstrap::formTextarea(array(
-		'name'=>'description',
-		'label'=>$L->g('Description'),
-		'value'=>isset($categoryMap['description'])?$categoryMap['description']:'',
-		'class'=>'',
-		'placeholder'=>'',
-		'tip'=>'',
-		'rows'=>3
-	));
-
-	echo Bootstrap::formInputText(array(
-		'name'=>'template',
-		'label'=>$L->g('Template'),
-		'value'=>isset($categoryMap['template'])?$categoryMap['template']:'',
-		'class'=>'',
-		'placeholder'=>'',
-		'tip'=>''
-	));
-
-	echo Bootstrap::formInputText(array(
-		'name'=>'newKey',
-		'label'=>$L->g('Friendly URL'),
-		'value'=>$categoryMap['key'],
-		'class'=>'',
-		'placeholder'=>'',
-		'tip'=>DOMAIN_CATEGORIES.$categoryMap['key']
-	));
-
-echo Bootstrap::formClose();
+echo Bootstrap::formInputText(array(
+	'name' => 'template',
+	'label' => $L->g('Template'),
+	'value' => isset($categoryMap['template']) ? $categoryMap['template'] : ''
+));
 
+echo Bootstrap::formInputText(array(
+	'name' => 'friendlyURL',
+	'label' => $L->g('Friendly URL'),
+	'value' => $categoryMap['key'],
+	'tip' => DOMAIN_CATEGORIES . $categoryMap['key']
+));
 ?>
 
-<!-- Modal for delete category -->
-<?php
-	echo Bootstrap::modal(array(
-		'buttonPrimary'=>$L->g('Delete'),
-		'buttonPrimaryClass'=>'btn-danger jsbuttonDeleteAccept',
-		'buttonSecondary'=>$L->g('Cancel'),
-		'buttonSecondaryClass'=>'btn-link',
-		'modalTitle'=>$L->g('Delete category'),
-		'modalText'=>$L->g('Are you sure you want to delete this category?'),
-		'modalId'=>'jsdeleteModal'
-	));
-?>
 <script>
-$(document).ready(function() {
-	// Delete content
-	$(".jsbuttonDeleteAccept").on("click", function() {
-		$("#jsaction").val("delete");
-		$("#jsform").submit();
+	$(document).ready(function() {
+		$('#btnSave').on('click', function() {
+			var name = $('#name').val();
+			var friendlyURL = $('#friendlyURL').val();
+
+			if ((name.length < 1) || (friendlyURL.length < 1)) {
+				showAlertError("<?php $L->p('Complete all fields') ?>");
+				return false;
+			}
+
+			var args = {
+				key: $('#key').val(),
+				name: name,
+				description: $('#description').val(),
+				friendlyURL: $('#friendlyURL').val(),
+				template: $('#template').val()
+			};
+			api.editCategory(args).then(function(key) {
+				logs('Category edited. Key: ' + key);
+				showAlertInfo("<?php $L->p('The changes have been saved') ?>");
+			});
+			return true;
+		});
+
+		$('#btnDelete').on('click', function() {
+			var key = $('#key').val();
+			logs('Deleting category. Key: ' + key);
+			var args = {
+				key: key
+			};
+			api.deleteCategory(args).then(function(key) {
+				logs('Category deleted. Key: ' + key);
+				window.location.replace(HTML_PATH_ADMIN_ROOT + 'categories');
+			});
+			return true;
+		});
 	});
-});
 </script>
\ No newline at end of file
diff --git a/bl-kernel/admin/views/editor.php b/bl-kernel/admin/views/editor.php
index f890f8c6..add39f42 100644
--- a/bl-kernel/admin/views/editor.php
+++ b/bl-kernel/admin/views/editor.php
@@ -89,11 +89,11 @@
 	}
 
 	function disableBtnSave() {
-		$('#btnSave').addClass('btn-primary-disabled').html('<i class="bi bi-check-square"></i><?php $L->p('Saved') ?>');
+		$('#btnSave').addClass('btn-primary-disabled').attr('data-current', 'saved').html('<i class="bi bi-check-square"></i><?php $L->p('Saved') ?>');
 	}
 
 	function enableBtnSave() {
-		$('#btnSave').removeClass('btn-primary-disabled').html('<i class="bi bi-save"></i><?php $L->p('Save') ?>');
+		$('#btnSave').removeClass('btn-primary-disabled').attr('data-current', 'unsaved').html('<i class="bi bi-save"></i><?php $L->p('Save') ?>');
 	}
 
 	// This function is to catch all key press and provides shortcuts
@@ -117,6 +117,11 @@
 			return false;
 		}
 
+		// Ctrl+ or Command+ or Alt+ or Shift+ or Option+
+		if (event.ctrlKey || event.metaKey || event.altKey || event.shiftKey) {
+			return true;
+		}
+
 		enableBtnSave();
 		return true;
 	}
@@ -128,10 +133,21 @@
 
 		// Main interface events
 		// ------------------------------------------------------------------------
+
+		// Catch all keypress for shortcuts or other actions
 		$(this).keydown(function(event) {
 			keypress(event);
 		});
 
+		// Warn the user to save the changes before leave
+		$(window).bind('beforeunload', function(e) {
+			if ($('#btnSave').attr('data-current')=='unsaved') {
+				(e || window.event).returnValue = '';
+				return '';
+			}
+			return undefined; // Return undefined to continue the unload
+		});
+
 		$('#btnSave').on('click', function() {
 			var args = {
 				title: $('#title').val(),
@@ -505,7 +521,7 @@
 			<!-- Toolbar > Save, Preview, Type and Options -->
 			<div id="editorToolbar" class="d-flex align-items-center mb-2">
 				<div id="editorToolbarLeft">
-					<button id="btnSave" type="button" class="btn btn-sm btn-primary btn-primary-disabled"><i class="bi bi-save"></i><?php $L->p('Saved') ?></button>
+					<button id="btnSave" type="button" data-current="saved" class="btn btn-sm btn-primary btn-primary-disabled"><i class="bi bi-save"></i><?php $L->p('Saved') ?></button>
 					<button id="btnPreview" type="button" class="btn btn-sm btn-primary"><i class="bi bi-box-arrow-up-right"></i><?php $L->p('Preview') ?></button>
 					<span id="btnCurrenType" class="ms-1">
 						<?php
diff --git a/bl-kernel/admin/views/editor/file-manager.php b/bl-kernel/admin/views/editor/file-manager.php
index 98f78a44..2e3095c1 100644
--- a/bl-kernel/admin/views/editor/file-manager.php
+++ b/bl-kernel/admin/views/editor/file-manager.php
@@ -135,7 +135,7 @@
 		logs('File Manager. Uploading file.');
 
 		// Check file type/extension
-		const validImageTypes = ['image/gif', 'image/jpeg', 'image/png', 'image/svg+xml'];
+		const validImageTypes = ['image/gif', 'image/jpeg', 'image/png', 'image/svg+xml', 'application/pdf'];
 		if (!validImageTypes.includes(file.type)) {
 			logs("File Manager. File type is not supported.");
 			showAlertError("<?php echo $L->g('File type is not supported. Allowed types:') . ' ' . implode(', ', $GLOBALS['ALLOWED_IMG_EXTENSION']) ?>");
diff --git a/bl-kernel/boot/init.php b/bl-kernel/boot/init.php
index e4cdea88..0bd98ae4 100644
--- a/bl-kernel/boot/init.php
+++ b/bl-kernel/boot/init.php
@@ -211,8 +211,9 @@ define('MARKDOWN_PARSER', $site->markdownParser());
 
 // --- PHP paths with dependency ---
 // This paths are absolutes for the OS
-define('THEME_DIR',			PATH_ROOT.'bl-themes'.DS.$site->theme().DS);
+define('THEME_DIR',				PATH_ROOT.'bl-themes'.DS.$site->theme().DS);
 define('THEME_DIR_PHP',			THEME_DIR.'php'.DS);
+define('THEME_DIR_TEMPLATES',	THEME_DIR.'templates'.DS);
 define('THEME_DIR_CSS',			THEME_DIR.'css'.DS);
 define('THEME_DIR_JS',			THEME_DIR.'js'.DS);
 define('THEME_DIR_IMG',			THEME_DIR.'img'.DS);
diff --git a/bl-kernel/boot/variables.php b/bl-kernel/boot/variables.php
index 9fa15e62..3ec91ebd 100644
--- a/bl-kernel/boot/variables.php
+++ b/bl-kernel/boot/variables.php
@@ -110,4 +110,4 @@ $GLOBALS['DB_TAGS_TYPES'] = array('published','static','sticky');
 $GLOBALS['ALLOWED_IMG_EXTENSION'] = array('gif', 'png', 'jpg', 'jpeg', 'svg');
 
 // Allowed image mime types
-$GLOBALS['ALLOWED_IMG_MIMETYPES'] = array('image/gif', 'image/png', 'image/jpeg', 'image/svg+xml');
+$GLOBALS['ALLOWED_IMG_MIMETYPES'] = array('image/gif', 'image/png', 'image/jpeg', 'image/svg+xml', 'application/pdf');
diff --git a/bl-kernel/functions.php b/bl-kernel/functions.php
index 495ff0f9..1c2d5d2a 100644
--- a/bl-kernel/functions.php
+++ b/bl-kernel/functions.php
@@ -1,5 +1,16 @@
 <?php defined('BLUDIT') or die('Bludit CMS.');
 
+/* ----------------------------------------------------------------------------
+	Global functions
+	These function provides connectivity beteween differens objects and databases.
+	These function should provide different checks and logic before add/edit/delete into the databases.
+
+	For example the creation of a user should check:
+	- if the user already exists
+	- if the username is not empty
+	- if the password match with the differents security rules such as min length
+/* ----------------------------------------------------------------------------
+
 /*	Create a new page === Bludit v4
 
 	@args			array			The array $args supports all the keys from the variable $dbFields of the class pages.class.php. If you don't pass all the keys, the default values are used.
@@ -118,7 +129,7 @@ function deletePage($key) {
 
 /*	Create a new category === Bludit v4
 
-	@args			array			The array $args supports all the keys from the variable $dbFields of the class categories.class.php. If you don't pass all the keys, the default values are used.
+	@args			array			Array => (name: string, template: string, description: string)
 	@returns		string/boolean	Returns the category key if the category is successfully created, FALSE otherwise
 */
 function createCategory($args) {
@@ -145,6 +156,82 @@ function createCategory($args) {
 	return false;
 }
 
+/*	Edit a category === Bludit v4
+
+	@args			array			Array => (key: string, name: string, friendlyURL: string, template: string, description: string)
+	@returns		string/boolean	Returns the category key if the category is successfully edited, FALSE otherwise
+*/
+function editCategory($args) {
+	global $pages;
+	global $categories;
+	global $syslog;
+
+	if (Text::isEmpty($args['key'])) {
+		Log::set(__FUNCTION__.LOG_SEP.'The category key is empty.', LOG_TYPE_ERROR);
+		return false;
+	}
+
+	if (Text::isEmpty($args['name'])) {
+		Log::set(__FUNCTION__.LOG_SEP.'The category name is empty.', LOG_TYPE_ERROR);
+		return false;
+	}
+
+	if (Text::isEmpty($args['friendlyURL'])) {
+		Log::set(__FUNCTION__.LOG_SEP.'The category friendlyURL is empty.', LOG_TYPE_ERROR);
+		return false;
+	}
+
+	$args['oldKey'] = $args['key'];
+	$args['newKey'] = $args['friendlyURL'];
+	$finalKey = $categories->edit($args);
+
+	if ($finalKey==false) {
+		Log::set(__FUNCTION__.LOG_SEP.'The category already exists.', LOG_TYPE_ERROR);
+		return false;
+	}
+
+	// Change the category key inside the pages database
+	if ($args['key']!==$finalKey) {
+		$pages->changeCategory($args['key'], $finalKey);
+	}
+
+	$syslog->add(array(
+		'dictionaryKey'=>'category-edited',
+		'notes'=>$finalKey
+	));
+
+	Log::set(__FUNCTION__.LOG_SEP.'Category edited.', LOG_TYPE_INFO);
+	return $finalKey;
+}
+
+/*	Delete a category === Bludit v4
+
+	@args			array			Array => (key: string)
+	@returns		boolean			Returns TRUE if the category was deleted, FALSE otherwise
+*/
+function deleteCategory($args) {
+	global $categories;
+	global $syslog;
+
+	if (Text::isEmpty($args['key'])) {
+		Log::set(__FUNCTION__.LOG_SEP.'The category key is empty.', LOG_TYPE_ERROR);
+		return false;
+	}
+
+	if ($categories->remove($args['key'])===false) {
+		Log::set(__FUNCTION__.LOG_SEP.'Something happened when you tried to delete the category.', LOG_TYPE_ERROR);
+		return false;
+	}
+
+	$syslog->add(array(
+		'dictionaryKey'=>'category-deleted',
+		'notes'=>$args['key']
+	));
+
+	Log::set(__FUNCTION__.LOG_SEP.'Category deleted.', LOG_TYPE_INFO);
+	return true;
+}
+
 /*	Create a new user === Bludit v4
 	This function should check everthing, such as empty username, emtpy password, password lenght, etc
 
@@ -727,56 +814,9 @@ function checkRole($allowRoles, $redirect=true) {
 
 
 
-function editCategory($args) {
-	global $L;
-	global $pages;
-	global $categories;
-	global $syslog;
 
-	if (Text::isEmpty($args['name']) || Text::isEmpty($args['newKey']) ) {
-		Alert::set($L->g('Empty fields'));
-		return false;
-	}
 
-	$newCategoryKey = $categories->edit($args);
 
-	if ($newCategoryKey==false) {
-		Alert::set($L->g('The category already exists'));
-		return false;
-	}
-
-	// Change the category key in the pages database
-	$pages->changeCategory($args['oldKey'], $newCategoryKey);
-
-	// Add to syslog
-	$syslog->add(array(
-		'dictionaryKey'=>'category-edited',
-		'notes'=>$newCategoryKey
-	));
-
-	Alert::set($L->g('The changes have been saved'));
-	return true;
-}
-
-function deleteCategory($args) {
-	global $L;
-	global $categories;
-	global $syslog;
-
-	// Remove the category by key
-	$categories->remove($args['oldKey']);
-
-	// Remove the category from the pages ? or keep it if the user want to recovery the category ?
-
-	// Add to syslog
-	$syslog->add(array(
-		'dictionaryKey'=>'category-deleted',
-		'notes'=>$args['oldKey']
-	));
-
-	Alert::set($L->g('The changes have been saved'));
-	return true;
-}
 
 // Returns an array with all the categories
 // By default, the database of categories is alphanumeric sorted
diff --git a/bl-kernel/helpers/bootstrap.class.php b/bl-kernel/helpers/bootstrap.class.php
index 5d1f211d..416649c6 100644
--- a/bl-kernel/helpers/bootstrap.class.php
+++ b/bl-kernel/helpers/bootstrap.class.php
@@ -2,6 +2,15 @@
 
 class Bootstrap {
 
+	public static function formInputHidden($args)
+	{
+		$name = $args['name'];
+		$id = isset($args['id'])?$args['id']:$name;
+		$value = isset($args['value'])?$args['value']:'';
+
+		return '<input type="hidden" id="'.$id.'" name="'.$name.'" value="'.$value.'">';
+	}
+
 	// Floating Labels
 	// https://getbootstrap.com/docs/5.0/forms/floating-labels/
 	public static function formFloatingLabels($args)
@@ -399,10 +408,7 @@ EOF;
 
 
 
-	public static function formInputHidden($args)
-	{
-		return '<input type="hidden" id="'.$args['name'].'" name="'.$args['name'].'" value="'.$args['value'].'">';
-	}
+
 
 	public static function alert($args)
 	{
diff --git a/bl-kernel/js/api.js b/bl-kernel/js/api.js
index 9ec56e99..33f86cbb 100644
--- a/bl-kernel/js/api.js
+++ b/bl-kernel/js/api.js
@@ -194,6 +194,56 @@ class API {
 		}
 	}
 
+	/*	Edit a category
+
+		@args					array		Arguments can be any of the fields from a category
+		@returns				string		The category key
+	*/
+	async editCategory(args) {
+		var url = this.apiURL + "categories/" + args['key'];
+		var body = Object.assign({}, this.body, args);
+		try {
+			var response = await fetch(url, {
+				credentials: "same-origin",
+				method: "PUT",
+				body: JSON.stringify(body),
+				headers: new Headers({
+					"Content-Type": "application/json"
+				})
+			});
+			var json = await response.json();
+			return json.data.key;
+		} catch (err) {
+			console.log(err);
+			return true;
+		}
+	}
+
+	/*	Delete a category
+
+		@args					array		Array => (key: string)
+		@returns				string		The category key deleted
+	*/
+	async deleteCategory(args) {
+		var url = this.apiURL + "categories/" + args['key'];
+		var body = this.body;
+		try {
+			var response = await fetch(url, {
+				credentials: "same-origin",
+				method: "DELETE",
+				body: JSON.stringify(body),
+				headers: new Headers({
+					"Content-Type": "application/json"
+				})
+			});
+			var json = await response.json();
+			return json.data.key;
+		} catch (err) {
+			console.log(err);
+			return true;
+		}
+	}
+
 	/*	Create a new user
 
 		@args					array		Arguments can be any of the fields from a user
diff --git a/bl-kernel/pages.class.php b/bl-kernel/pages.class.php
index 3f05d252..6a67f33e 100644
--- a/bl-kernel/pages.class.php
+++ b/bl-kernel/pages.class.php
@@ -785,7 +785,12 @@ class Pages extends dbJSON {
 		return $tmp;
 	}
 
-	// Change all pages with the old category key to the new category key
+	/*	Change all pages linked to the old category key to the new category key === Bludit v4
+
+		@oldCategoryKey		string		The old category key
+		@newCategoryKey		string		The new category key
+		@returns			boolean		Returns TRUE if the database was saved, FALSE otherwise
+	*/
 	public function changeCategory($oldCategoryKey, $newCategoryKey)
 	{
 		foreach ($this->db as $key=>$value) {
diff --git a/bl-kernel/pagex.class.php b/bl-kernel/pagex.class.php
index 9822ad45..3423108a 100644
--- a/bl-kernel/pagex.class.php
+++ b/bl-kernel/pagex.class.php
@@ -234,9 +234,17 @@ class Page {
 		}
 	}
 
+	/*	Returns the template for the page === Bludit v4
+
+		@returns		string/boolean	Returns the template for the page or FALSE if the page haven't a template assigned
+	*/
 	public function template()
 	{
-		return $this->getValue('template');
+		$template = $this->getValue('template');
+		if (empty($template)) {
+			return false;
+		}
+		return $template;
 	}
 
 	// Returns the description field
diff --git a/bl-languages/en.json b/bl-languages/en.json
index 66f7ea4f..86d4d0ec 100644
--- a/bl-languages/en.json
+++ b/bl-languages/en.json
@@ -225,7 +225,7 @@
     "label": "Label",
     "links": "Links",
     "this-title-is-almost-always-used-in-the-sidebar-of-the-site": "This title is almost always used in the sidebar of the site.",
-    "password-must-be-at-least-6-characters-long": "Password must be at least 6 characters long.",
+    "password-must-be-at-least-6-characters-long": "Password must be at least 6 characters long",
     "ip-address-has-been-blocked": "IP address has been blocked",
     "try-again-in-a-few-minutes": "Try again in a few minutes",
     "content-published-from-scheduler": "Content published from scheduler",
@@ -240,7 +240,7 @@
     "delete-the-user-and-all-his-content": "Delete the user and all of their content",
     "user-disabled": "User disabled",
     "user-password-changed": "User password changed",
-    "the-password-and-confirmation-password-do-not-match": "The password and confirmation password do not match.",
+    "the-password-and-confirmation-password-do-not-match": "The password and confirmation password do not match",
     "scheduled-content": "Scheduled content",
     "there-are-no-scheduled-content": "There are no scheduled content.",
     "new-content-created": "New content created",
diff --git a/bl-plugins/api/plugin.php b/bl-plugins/api/plugin.php
index d5ef801b..272a4f9f 100644
--- a/bl-plugins/api/plugin.php
+++ b/bl-plugins/api/plugin.php
@@ -189,6 +189,16 @@ class pluginAPI extends Plugin {
 		elseif ( ($method==='POST') && ($parameters[0]==='categories') && empty($parameters[1]) && $writePermissions ) {
 			$data = $this->createCategory($inputs);
 		}
+		// (PUT) /api/categories/<key>
+		elseif ( ($method==='PUT') && ($parameters[0]==='categories') && !empty($parameters[1]) && $writePermissions ) {
+			$inputs['key'] = $parameters[1];
+			$data = $this->editCategory($inputs);
+		}
+		// (DELETE) /api/categories/<key>
+		elseif ( ($method==='DELETE') && ($parameters[0]==='categories') && !empty($parameters[1]) && $writePermissions ) {
+			$inputs['key'] = $parameters[1];
+			$data = $this->deleteCategory($inputs);
+		}
 		// (GET) /api/users
 		elseif ( ($method==='GET') && ($parameters[0]==='users') && empty($parameters[1]) ) {
 			$data = $this->getUsers();
@@ -644,9 +654,11 @@ class pluginAPI extends Plugin {
 		);
 	}
 
+	/*	Create a new category === Bludit v4
+		Referer to the function createCategory() from functions.php
+	*/
 	private function createCategory($args)
 	{
-		// This function is defined on functions.php
 		$key = createCategory($args);
 		if ($key===false) {
 			return array(
@@ -662,6 +674,45 @@ class pluginAPI extends Plugin {
 		);
 	}
 
+	/*	Edit a category === Bludit v4
+		Referer to the function editCategory() from functions.php
+	*/
+	private function editCategory($args)
+	{
+		$key = editCategory($args);
+		if ($key===false) {
+			return array(
+				'status'=>'1',
+				'message'=>'An error occurred while trying to edit the category.'
+			);
+		}
+
+		return array(
+			'status'=>'0',
+			'message'=>'Category edited.',
+			'data'=>array('key'=>$key)
+		);
+	}
+
+	/*	Delete a category === Bludit v4
+		Referer to the function deleteCategory() from functions.php
+	*/
+	private function deleteCategory($args)
+	{
+		if (deleteCategory($args)) {
+			return array(
+				'status'=>'0',
+				'message'=>'Category deleted.',
+				'data'=>array('key'=>$args['key'])
+			);
+		}
+
+		return array(
+			'status'=>'1',
+			'message'=>'An error occurred while trying to delete the category.'
+		);
+	}
+
 	/*
 	 | Returns the user profile
 	 |
diff --git a/bl-themes/blogx/index.php b/bl-themes/blogx/index.php
index 71645914..4cd54b7d 100755
--- a/bl-themes/blogx/index.php
+++ b/bl-themes/blogx/index.php
@@ -26,7 +26,12 @@
 				// If the user is watching a particular page/post the variable takes the value "page"
 				// If the user is watching the frontpage the variable takes the value "home"
 				if ($WHERE_AM_I == 'page') {
-					include(THEME_DIR_PHP.'page.php');
+					$template = $page->template();
+					if (($template) && file_exists(THEME_DIR_TEMPLATES.$template)) {
+						include(THEME_DIR_TEMPLATES.$template);
+					} else {
+						include(THEME_DIR_PHP.'page.php');
+					}
 				} else {
 					include(THEME_DIR_PHP.'home.php');
 				}