Marcin Grabias
--- a/src/Entity/CourseStatus.php
+++ b/src/Entity/CourseStatus.php
      ->setSetting('handler', 'default')
      ->setRequired(TRUE);

-    $fields['gid'] = BaseFieldDefinition::create('entity_reference')
-      ->setLabel(\t('Training'))
-      ->setDescription(\t('The Training of the Course Status entity.'))
+    $fields['gid'] = BaseFieldDefinition::create('lms_revision_reference')
--- a/src/Form/LmsSettingsForm.php
+++ b/src/Form/LmsSettingsForm.php
      '#description' => $this->t('This allows students to reenter finished courses that still need manual grading by a teacher and make changes to their answers. NOTE: If changed on a site with existing courses that are already in progress, caches need to be cleared.'),
      '#config_target' => 'lms.settings:allow_to_enter_ungraded',
    ];
+    $form['use_revisions'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Use revisions'),
+      '#description' => $this->t('When this is enabled and the current user starts a course, a lesson or an activity, the currently published revision is locked for the student and updates to those entities while the course is in progress do not affect the student experience in any way.'),
--- a/src/Plugin/Field/FieldType/RevisionReferenceItem.php 0 → 100644
+++ b/src/Plugin/Field/FieldType/RevisionReferenceItem.php 0 → 100644
+declare(strict_types=1);
+
+namespace Drupal\lms\Plugin\Field\FieldType;
+
+use Drupal\Core\Entity\Plugin\DataType\EntityReference;
+use Drupal\Core\Entity\RevisionableInterface;
+use Drupal\Core\Field\Attribute\FieldType;
+use Drupal\Core\Field\EntityReferenceFieldItemList;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\TypedData\DataReferenceDefinition;
+use Drupal\Core\TypedData\DataReferenceTargetDefinition;
+
+/**
+ * Defines the 'entity_reference' entity field type.