diff --git a/include/misc.h b/include/misc.h
index 90d7046d3..6ce214e61 100644
--- a/include/misc.h
+++ b/include/misc.h
@@ -102,6 +102,16 @@ OF THIS SOFTWARE.
 
 typedef uint32_t ATOM;
 
+/* @brief generic X return code
+ *
+ * this type is should be used instead of plain int for all functions
+ * returning and X error code (that's possibly sent to the client),
+ * in order to make return value semantics clear to the humen reader.
+ *
+ * part of public SDK / driver API.
+ */
+typedef int XRetCode;
+
 #ifndef TRUE
 #define TRUE 1
 #define FALSE 0