diff --git a/src/modules/tm/h_table.c b/src/modules/tm/h_table.c
index 6149c363d4b..74e47ef7d89 100644
--- a/src/modules/tm/h_table.c
+++ b/src/modules/tm/h_table.c
@@ -514,6 +514,7 @@ struct s_table *init_hash_table()
  * backup xdata from/to msg context to local var and use T lists
  * - mode = 0 - from msg context to _txdata and use T lists
  * - mode = 1 - restore to msg context from _txdata
+ * the function can be also used to restore the core context from transacation data
  */
 void tm_xdata_swap(tm_cell_t *t, tm_xlinks_t *xd, int mode)
 {