diff --git a/device_mapper/misc/dm-ioctl.h b/device_mapper/misc/dm-ioctl.h
index cc2374c36..c00fa5b4f 100644
--- a/device_mapper/misc/dm-ioctl.h
+++ b/device_mapper/misc/dm-ioctl.h
@@ -194,8 +194,22 @@ struct dm_name_list {
 	uint32_t next;		/* offset to the next record from
 				   the _start_ of this */
 	char name[0];
+
+	/*
+	 * The following members can be accessed by taking a pointer that
+	 * points immediately after the terminating zero character in "name"
+	 * and aligning this pointer to next 8-byte boundary.
+	 * Uuid is present if the flag DM_NAME_LIST_FLAG_HAS_UUID is set.
+	 *
+	 * uint32_t event_nr;
+	 * uint32_t flags;
+	 * char uuid[0];
+	 */
 };
 
+#define DM_NAME_LIST_FLAG_HAS_UUID		1
+#define DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID	2
+
 /*
  * Used to retrieve the target versions
  */