diff --git a/library/MGCP_Types.ttcn b/library/MGCP_Types.ttcn
index 22141f4..9d1a4e1 100644
--- a/library/MGCP_Types.ttcn
+++ b/library/MGCP_Types.ttcn
@@ -1,4 +1,16 @@
 module MGCP_Types {
+
+/* Definition of abstract types for the MGCP protocol as specified in
+ * IETF RFC 3435.  Uses the TITAN "TEXT" codec to auto-generate encoder/decoder
+ * functions, as well as the SDP type definitions and coder from Ericsson.
+ *
+ * (C) 2017 by Harald Welte <laforge@gnumonks.org>
+ * All rights reserved.
+ *
+ * Released under the terms of GNU General Public License, Version 2 or
+ * (at your option) any later version.
+ */
+
 	import from SDP_Types all;
 
 	type charstring MgcpVerb ("EPCF", "CRCX", "MDCX", "DLCX", "RQNT", "NTFY",