diff --git a/config/core.entity_form_display.paragraph.document_chapter.default.yml b/config/core.entity_form_display.paragraph.document_chapter.default.yml
index 20dfcfbc..e62db610 100644
--- a/config/core.entity_form_display.paragraph.document_chapter.default.yml
+++ b/config/core.entity_form_display.paragraph.document_chapter.default.yml
@@ -5,6 +5,7 @@ dependencies:
   config:
     - entity_browser.browser.articles
     - field.field.paragraph.document_chapter.field_articles
+    - field.field.paragraph.document_chapter.field_hide_from_navigation
     - field.field.paragraph.document_chapter.field_short_title
     - field.field.paragraph.document_chapter.field_summary
     - field.field.paragraph.document_chapter.field_tags
@@ -51,6 +52,7 @@ third_party_settings:
         - field_summary
         - field_tags
         - status
+        - field_hide_from_navigation
       label: 'Chapter properties'
       region: content
       parent_name: group_tabs
@@ -88,11 +90,11 @@ content:
     weight: 2
     region: content
     settings:
+      open: true
       entity_browser: articles
       field_widget_display: label
       field_widget_edit: '1'
       field_widget_remove: '1'
-      open: '1'
       selection_mode: selection_append
       additional_fields:
         options:
@@ -100,6 +102,13 @@ content:
       field_widget_replace: 0
       field_widget_display_settings: {  }
     third_party_settings: {  }
+  field_hide_from_navigation:
+    type: boolean_checkbox
+    weight: 8
+    region: content
+    settings:
+      display_label: true
+    third_party_settings: {  }
   field_short_title:
     type: string_textfield
     weight: 22
diff --git a/config/core.entity_view_display.paragraph.document_chapter.default.yml b/config/core.entity_view_display.paragraph.document_chapter.default.yml
index 8bf9c7bb..97348b77 100644
--- a/config/core.entity_view_display.paragraph.document_chapter.default.yml
+++ b/config/core.entity_view_display.paragraph.document_chapter.default.yml
@@ -4,6 +4,7 @@ status: true
 dependencies:
   config:
     - field.field.paragraph.document_chapter.field_articles
+    - field.field.paragraph.document_chapter.field_hide_from_navigation
     - field.field.paragraph.document_chapter.field_short_title
     - field.field.paragraph.document_chapter.field_summary
     - field.field.paragraph.document_chapter.field_tags
@@ -23,6 +24,16 @@ content:
     third_party_settings: {  }
     weight: 2
     region: content
+  field_hide_from_navigation:
+    type: boolean
+    label: above
+    settings:
+      format: default
+      format_custom_false: ''
+      format_custom_true: ''
+    third_party_settings: {  }
+    weight: 3
+    region: content
   field_summary:
     type: basic_string
     label: hidden
diff --git a/config/core.entity_view_display.paragraph.document_chapter.preview.yml b/config/core.entity_view_display.paragraph.document_chapter.preview.yml
index 3d01ed9a..f943842a 100644
--- a/config/core.entity_view_display.paragraph.document_chapter.preview.yml
+++ b/config/core.entity_view_display.paragraph.document_chapter.preview.yml
@@ -5,6 +5,7 @@ dependencies:
   config:
     - core.entity_view_mode.paragraph.preview
     - field.field.paragraph.document_chapter.field_articles
+    - field.field.paragraph.document_chapter.field_hide_from_navigation
     - field.field.paragraph.document_chapter.field_short_title
     - field.field.paragraph.document_chapter.field_summary
     - field.field.paragraph.document_chapter.field_tags
@@ -42,6 +43,7 @@ content:
     weight: 0
     region: content
 hidden:
+  field_hide_from_navigation: true
   field_short_title: true
   field_summary: true
   field_tags: true
diff --git a/config/field.field.paragraph.document_chapter.field_hide_from_navigation.yml b/config/field.field.paragraph.document_chapter.field_hide_from_navigation.yml
new file mode 100644
index 00000000..b2f8a455
--- /dev/null
+++ b/config/field.field.paragraph.document_chapter.field_hide_from_navigation.yml
@@ -0,0 +1,21 @@
+uuid: eb6f7af0-4f35-4cd0-a789-82f1e6ad8513
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.storage.paragraph.field_hide_from_navigation
+    - paragraphs.paragraphs_type.document_chapter
+id: paragraph.document_chapter.field_hide_from_navigation
+field_name: field_hide_from_navigation
+entity_type: paragraph
+bundle: document_chapter
+label: 'Hide in document navigation'
+description: 'If checked, the chapter is marked as part of the document but should not be automatically included in the documents navigation. Useful for example for articles that are mostly shown as sub-articles in other article pages.'
+required: false
+translatable: false
+default_value: {  }
+default_value_callback: ''
+settings:
+  on_label: 'On'
+  off_label: 'Off'
+field_type: boolean
diff --git a/config/field.storage.paragraph.field_hide_from_navigation.yml b/config/field.storage.paragraph.field_hide_from_navigation.yml
new file mode 100644
index 00000000..80674f3d
--- /dev/null
+++ b/config/field.storage.paragraph.field_hide_from_navigation.yml
@@ -0,0 +1,18 @@
+uuid: 0472638f-b863-4754-a06c-89b9ba148312
+langcode: en
+status: true
+dependencies:
+  module:
+    - paragraphs
+id: paragraph.field_hide_from_navigation
+field_name: field_hide_from_navigation
+entity_type: paragraph
+type: boolean
+settings: {  }
+module: core
+locked: false
+cardinality: 1
+translatable: true
+indexes: {  }
+persist_with_no_fields: false
+custom_storage: false
diff --git a/html/modules/custom/gho_fields/gho_fields.deploy.php b/html/modules/custom/gho_fields/gho_fields.deploy.php
index b2e91590..0403c990 100644
--- a/html/modules/custom/gho_fields/gho_fields.deploy.php
+++ b/html/modules/custom/gho_fields/gho_fields.deploy.php
@@ -23,7 +23,7 @@ function gho_fields_deploy_post_rename_datawrapper_fields(&$sandbox) {
     $paragraph->get('field_show_interactive_content')->setValue([
       'value' => $paragraph->get('field_show_datawrapper')->value,
     ]);
-    $paragraph->isSyncing();
+    $paragraph->setSyncing(TRUE);
     $paragraph->save();
   }
 }
@@ -53,7 +53,7 @@ function gho_fields_deploy_migrate_bottom_figure_rows() {
         'value' => $figure->second,
       ]);
     }
-    $paragraph->isSyncing();
+    $paragraph->setSyncing(TRUE);
     $paragraph->save();
 
     foreach ($paragraph->getTranslationLanguages() as $language) {
@@ -74,7 +74,7 @@ function gho_fields_deploy_migrate_bottom_figure_rows() {
           'value' => $figure->second,
         ]);
       }
-      $translated_paragraph->isSyncing();
+      $translated_paragraph->setSyncing(TRUE);
       $translated_paragraph->save();
     }
   }
diff --git a/html/modules/custom/ncms_graphql/graphql/ncms_schema_extension.base.graphqls b/html/modules/custom/ncms_graphql/graphql/ncms_schema_extension.base.graphqls
index 74514c23..87d4afa7 100644
--- a/html/modules/custom/ncms_graphql/graphql/ncms_schema_extension.base.graphqls
+++ b/html/modules/custom/ncms_graphql/graphql/ncms_schema_extension.base.graphqls
@@ -87,6 +87,7 @@ type DocumentChapter {
   title: String
   title_short: String
   summary: String
+  hidden: Boolean
   articles: [Article]
 }
 
diff --git a/html/modules/custom/ncms_graphql/ncms_graphql.deploy.php b/html/modules/custom/ncms_graphql/ncms_graphql.deploy.php
index 8f5c2ffc..d06ba712 100644
--- a/html/modules/custom/ncms_graphql/ncms_graphql.deploy.php
+++ b/html/modules/custom/ncms_graphql/ncms_graphql.deploy.php
@@ -20,7 +20,7 @@ function ncms_graphql_deploy_set_auto_visible_flag(&$sandbox) {
     $node->get('field_automatically_visible')->setValue([
       'value' => 1,
     ]);
-    $node->isSyncing();
+    $node->setSyncing(TRUE);
     $node->save();
   }
 }
diff --git a/html/modules/custom/ncms_graphql/src/Plugin/GraphQL/SchemaExtension/NcmsSchemaExtension.php b/html/modules/custom/ncms_graphql/src/Plugin/GraphQL/SchemaExtension/NcmsSchemaExtension.php
index 48ae8abb..a78fdaad 100644
--- a/html/modules/custom/ncms_graphql/src/Plugin/GraphQL/SchemaExtension/NcmsSchemaExtension.php
+++ b/html/modules/custom/ncms_graphql/src/Plugin/GraphQL/SchemaExtension/NcmsSchemaExtension.php
@@ -651,6 +651,12 @@ private function addFieldResolverDocumentChapter(ResolverRegistryInterface $regi
         ->map('value', $builder->fromParent())
         ->map('path', $builder->fromValue('field_summary.value')),
     );
+    $registry->addFieldResolver('DocumentChapter', 'hidden',
+      $builder->produce('property_path')
+        ->map('type', $builder->fromValue('entity:node'))
+        ->map('value', $builder->fromParent())
+        ->map('path', $builder->fromValue('field_hide_from_navigation.value')),
+    );
     $registry->addFieldResolver('DocumentChapter', 'articles',
       $builder->produce('entity_reference')
         ->map('entity', $builder->fromParent())
diff --git a/html/modules/custom/ncms_ui/ncms_ui.deploy.php b/html/modules/custom/ncms_ui/ncms_ui.deploy.php
index 6e0f52fc..24406899 100644
--- a/html/modules/custom/ncms_ui/ncms_ui.deploy.php
+++ b/html/modules/custom/ncms_ui/ncms_ui.deploy.php
@@ -120,7 +120,7 @@ function ncms_ui_deploy_set_content_space_nodes(&$sandbox) {
     $node->get('field_content_space')->setValue([
       'target_id' => $term->id(),
     ]);
-    $node->isSyncing();
+    $node->setSyncing(TRUE);
     $node->save();
   }
 }
@@ -199,7 +199,7 @@ function ncms_ui_deploy_set_content_space_nodes_orphaned(&$sandbox) {
     $node->get('field_content_space')->setValue([
       'target_id' => $term->id(),
     ]);
-    $node->isSyncing();
+    $node->setSyncing(TRUE);
     $node->save();
   }
 }
@@ -225,7 +225,7 @@ function ncms_ui_deploy_set_content_space_media(&$sandbox) {
     $entity->get('field_content_space')->setValue([
       'target_id' => $term->id(),
     ]);
-    $entity->isSyncing();
+    $entity->setSyncing(TRUE);
     $entity->save();
   }
 }
@@ -243,3 +243,54 @@ function ncms_ui_deploy_remove_obsolete_admin_menu_links() {
     $menu_link->delete();
   }
 }
+
+/**
+ * Correct the changed date for content.
+ *
+ * The changed date got corrupted by
+ * ncms_graphql_deploy_set_auto_visible_flag().
+ */
+function ncms_ui_deploy_correct_changed_date(&$sandbox) {
+  /** @var \Drupal\Node\NodeStorageInterface $node_storage */
+  $node_storage = \Drupal::entityTypeManager()->getStorage('node');
+
+  /** @var \Drupal\node\NodeInterface[] $nodes */
+  $nodes = $node_storage->loadByProperties([
+    'type' => ['article', 'document'],
+  ]);
+
+  foreach ($nodes as $node) {
+    if (!$node instanceof ContentBase) {
+      continue;
+    }
+
+    // Get all revision ids.
+    $revision_ids = $node_storage->revisionIds($node);
+    if (count($revision_ids) < 2) {
+      continue;
+    }
+    $revision_ids = array_values(array_reverse($revision_ids));
+
+    /** @var \Drupal\ncms_ui\Entity\Content\ContentBase $revision */
+    $revision = $node_storage->loadRevision($revision_ids[0]);
+    if (!$revision) {
+      continue;
+    }
+
+    if ($revision->getChangedTime() != 1698930576) {
+      continue;
+    }
+
+    // Update the changed date of the current revision.
+    $revision->setChangedTime($revision->getRevisionCreationTime());
+    $revision->setNewRevision(FALSE);
+    $revision->setSyncing(TRUE);
+    $revision->save();
+
+    // Update the changed date of the node.
+    $node->setChangedTime($revision->getRevisionCreationTime());
+    $node->setNewRevision(FALSE);
+    $node->setSyncing(TRUE);
+    $node->save();
+  }
+}
diff --git a/html/modules/custom/ncms_ui/ncms_ui.module b/html/modules/custom/ncms_ui/ncms_ui.module
index dfd445fc..ac9dba05 100644
--- a/html/modules/custom/ncms_ui/ncms_ui.module
+++ b/html/modules/custom/ncms_ui/ncms_ui.module
@@ -13,6 +13,7 @@ use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Markup;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Url;
 use Drupal\media\MediaInterface;
@@ -305,6 +306,22 @@ function ncms_ui_preprocess_layout_paragraphs_builder_component_menu(&$variables
   $variables['types']['layout'] = [];
 }
 
+/**
+ * Implements hook_preprocess_hook().
+ */
+function ncms_ui_preprocess_field__paragraph__field_title__document_chapter(&$variables) {
+  if ($variables['element']['#view_mode'] != 'preview') {
+    return;
+  }
+  /** @var \Drupal\paragraphs\Entity\Paragraph $paragraph */
+  $paragraph = $variables['element']['#object'];
+  // If the chapter is marked as hidden, add a note to the title.
+  if ($paragraph->hasField('field_hide_from_navigation') && $paragraph->get('field_hide_from_navigation')->value) {
+    $variables['items'][0]['content']['#template'] .= Markup::create('<span style="font-style: italic; font-weight: normal;"> ({{ note }})</span>');
+    $variables['items'][0]['content']['#context']['note'] = t('Hidden from navigation');
+  }
+}
+
 /**
  * Implements hook_form_FORM_ID_alter().
  */
diff --git a/html/modules/custom/ncms_ui/ncms_ui.post_update.php b/html/modules/custom/ncms_ui/ncms_ui.post_update.php
index 7274358b..fa284242 100644
--- a/html/modules/custom/ncms_ui/ncms_ui.post_update.php
+++ b/html/modules/custom/ncms_ui/ncms_ui.post_update.php
@@ -26,7 +26,7 @@ function ncms_ui_post_update_set_content_space_nodes(&$sandbox) {
     $node->get('field_content_space')->setValue([
       'target_id' => $term->id(),
     ]);
-    $node->isSyncing();
+    $node->setSyncing(TRUE);
     $node->save();
   }
 }