diff --git a/netopeer/voltha-transapi/voltha-schematron.xsl b/netopeer/voltha-transapi/voltha-schematron.xsl
index fd93ce7..68d8e9c 100644
--- a/netopeer/voltha-transapi/voltha-schematron.xsl
+++ b/netopeer/voltha-transapi/voltha-schematron.xsl
@@ -1,3 +1,18 @@
+<!--
+Copyright 2017-present Open Networking Foundation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
 <?xml version="1.0" standalone="yes"?>
 <!--This XSLT was automatically generated from a Schematron schema.-->
 <axsl:stylesheet xmlns:date="http://exslt.org/dates-and-times" xmlns:dyn="http://exslt.org/dynamic" xmlns:exsl="http://exslt.org/common" xmlns:math="http://exslt.org/math" xmlns:random="http://exslt.org/random" xmlns:regexp="http://exslt.org/regular-expressions" xmlns:set="http://exslt.org/sets" xmlns:str="http://exslt.org/strings" xmlns:axsl="http://www.w3.org/1999/XSL/Transform" xmlns:sch="http://www.ascc.net/xml/schematron" xmlns:iso="http://purl.oclc.org/dsdl/schematron" xmlns:voltha="urn:opencord:params:xml:ns:voltha:voltha" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" extension-element-prefixes="date dyn exsl math random regexp set str" version="1.0"><!--Implementers: please note that overriding process-prolog or process-root is