diff --git a/include/dbclean.php b/include/dbclean.php
index 024b845f7d..8da78d64b5 100644
--- a/include/dbclean.php
+++ b/include/dbclean.php
@@ -35,6 +35,19 @@ function dbclean_run(&$argv, &$argc) {
 
 /**
  * @brief Remove orphaned database entries
+ * @param integer $stage What should be deleted?
+ *
+ * Values for $stage:
+ * ------------------
+ * 1:	Old global item entries from item table without user copy.
+ * 2:	Items without parents.
+ * 3:	Orphaned data from thread table.
+ * 4:	Orphaned data from notify table.
+ * 5:	Orphaned data from notify-threads table.
+ * 6:	Orphaned data from sign table.
+ * 7:	Orphaned data from term table.
+ * 8:	Expired threads.
+ * 9:	Old global item entries from expired threads
  */
 function remove_orphans($stage = 0) {
 	global $db;