--- /dev/null
+<?php
+
+namespace Drupal\metatag_app_links\Plugin\metatag\Tag;
+
+use Drupal\metatag\Plugin\metatag\Tag\MetaPropertyBase;
+
+/**
+ * The AppLinks iOS App URL scheme meta tag.
+ *
+ * @MetatagTag(
+ * id = "al_ios_url",
+ * label = @Translation("iOS app URL scheme"),
+ * description = @Translation("A custom scheme for the iOS app. <strong>This attribute is required by the app Links specification.</strong>"),
+ * name = "al:ios:url",
+ * group = "app_links",
+ * weight = 1,
+ * type = "string",
+ * secure = FALSE,
+ * multiple = FALSE
+ * )
+ */
+class AlIosUrl extends MetaPropertyBase {
+ // Nothing here yet. Just a placeholder class for a plugin.
+}