diff --git a/public_html/wp-content/plugins/camptix/addons/shortcodes.php b/public_html/wp-content/plugins/camptix/addons/shortcodes.php
index de6a04505f..ff82b92406 100644
--- a/public_html/wp-content/plugins/camptix/addons/shortcodes.php
+++ b/public_html/wp-content/plugins/camptix/addons/shortcodes.php
@@ -225,6 +225,7 @@ public function sanitize_attendees_atts( $attr ) {
 			$attr['orderby'] = 'title';
 		}
 
+		// ID of ticket types, not invididual tickets. i.e. from wp-admin/edit.php?post_type=tix_ticket.
 		if ( $attr['tickets'] ) {
 			$attr['tickets'] = array_map( 'intval', explode( ',', $attr['tickets'] ) );
 		}