--- /dev/null
+<?php
+
+namespace Drupal\metatag_open_graph\Plugin\metatag\Tag;
+
+use \Drupal\metatag\Plugin\metatag\Tag\MetaPropertyBase;
+
+/**
+ * Provides a plugin for the 'og:locale:alternate' meta tag.
+ *
+ * @MetatagTag(
+ * id = "og_locale_alternative",
+ * label = @Translation("Alternative locales"),
+ * description = @Translation("Other locales this content is available in, must be in the format language_TERRITORY, e.g. 'fr_FR'."),
+ * name = "og:locale:alternate",
+ * group = "open_graph",
+ * weight = 27,
+ * type = "string",
+ * secure = FALSE,
+ * multiple = TRUE
+ * )
+ */
+class OgLocaleAlternative extends MetaPropertyBase {
+ // Nothing here yet. Just a placeholder class for a plugin.
+}