diff -r 3d68bb0047a1 -r ec403cf308eb master/pdo_list.c
--- a/master/pdo_list.c	Tue Feb 12 15:30:34 2013 +0100
+++ b/master/pdo_list.c	Tue Feb 12 15:46:43 2013 +0100
@@ -237,6 +237,8 @@
 /*****************************************************************************/
 
 /** Finds a PDO with the given index.
+ *
+ * \return Search result, or NULL.
  */
 ec_pdo_t *ec_pdo_list_find_pdo(
         const ec_pdo_list_t *pl, /**< PDO list. */
@@ -257,6 +259,8 @@
 /*****************************************************************************/
 
 /** Finds a PDO with the given index and returns a const pointer.
+ *
+ * \return Search result, or NULL.
  */
 const ec_pdo_t *ec_pdo_list_find_pdo_const(
         const ec_pdo_list_t *pl, /**< PDO list. */
@@ -279,6 +283,8 @@
 /** Finds a PDO via its position in the list.
  *
  * Const version.
+ *
+ * \return Zero on success, otherwise a negative error code.
  */
 const ec_pdo_t *ec_pdo_list_find_pdo_by_pos_const(
         const ec_pdo_list_t *pl, /**< PDO list. */