WerdsWords · August 4, 2013 01:37 · Aug 4, 2013
diff --git a/nav_menu_meta_box_object.php b/nav_menu_meta_box_object.php
@@ -0,0 +1,22 @@
+<?php
+/**
+ * Rename category and tag menus accordion sections.
+ *
+ * @see wp_ajax_menu_get_metabox()
+ *
+ * @param object $item_object The menu meta box object, e.g. post, page, category, post_tag.
+ *
+ * @return object The filtered meta box object.
+ */
+function wpdocs_modify_categories_menu_box( $item_object ) {
+	// 'Categories' becomes 'Category Archives'
+	if ( 'category' == $item_object->name )
+		$item_object->labels->name = __( 'Category Archives', 'yourtextdomain' );
+
+	// 'Tags' becomes 'Tag Archives'
+	if ( 'post_tag' == $item_object->name )
+		$item_object->labels->name = __( 'Tag Archives', 'yourtextdomain' );
+
+	return $item_object;
+}
+add_filter( 'nav_menu_meta_box_object', 'wpdocs_modify_categories_menu_box' );