diff --git a/core/modules/migrate/src/Plugin/migrate/process/MenuLinkParent.php b/core/modules/migrate/src/Plugin/migrate/process/MenuLinkParent.php
index a998067..ff23640 100644
--- a/core/modules/migrate/src/Plugin/migrate/process/MenuLinkParent.php
+++ b/core/modules/migrate/src/Plugin/migrate/process/MenuLinkParent.php
@@ -17,12 +17,14 @@
 /**
  * Determines the parent of a menu link.
  *
+ * If the parent cannot be ascertained then a MigrateSkipRowException is thrown.
+ *
  * The source is an array of three values:
- *   - parent_id: The numeric ID of the parent menu link, or 0 if the link is at
- *     the top level of its menu.
- *   - menu_name: The menu name. All links with the same menu name (such as
- *     'navigation') are part of the same menu.
- *   - parent_link_path: The Drupal path or external URL this link points to.
+ * - parent_id: The numeric ID of the parent menu link, or 0 if the link is at
+ *   the top level of its menu.
+ * - menu_name: The menu name. All links with the same menu name (such as
+ *   'navigation') are part of the same menu.
+ * - parent_link_path: The Drupal path or external URL this link points to.
  *
  * Example:
  *