diff --git a/privacyidea-checkotp b/privacyidea-checkotp
index 95559c6..b9928c2 100755
--- a/privacyidea-checkotp
+++ b/privacyidea-checkotp
@@ -1,39 +1,35 @@
 #!/bin/bash
-
+#
 # privacyidea-checkotp	- shell implementation of the PrivacyIDEA OTP check for
 #			  integration with FreeRadius on systems without perl
 #
-# Version 1.0, latest version available from:
+# Version 1.0, latest version, documentation and bugtracker available at:
 #		https://gitlab.lindenaar.net/scripts/privacyidea-checkotp
 #
 # Copyright (c) 2015 Frederik Lindenaar
 #
 # This script is free software: you can redistribute and/or modify it under the
-# terms of the GNU General Public License as published by the Free Software
-# Foundation, either version 3 of the License, or (at your option) any later version.
+# terms of version 3 of the GNU General Public License as published by the Free
+# Software Foundation, or (at your option) any later version of the license.
 #
-# This script is distributed in the hope that it will be useful, but WITHOUT ANY
+# This script is distributed in the hope that it will be useful but WITHOUT ANY
 # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 # A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License along with
-# this program.  If not, see <http://www.gnu.org/licenses/>.
+# this program.  If not, visit <http://www.gnu.org/licenses/> to download it.
 
 # If called for the Outbound-User Service type, exit immediately (not supported)
 if [ "$SERVICE_TYPE" = "Outbound-User" ]; then
   exit 8
 fi
 
-# Simple script to validate an OTP with PrivacyIDEA
-
+# Obtain parameters from command line or environment variables
 if [ $# = 1 ]; then
   URL="$1/validate/check"
   LOGIN=`echo "${STRIPPED_USER_NAME:-$USER_NAME}" | sed 's/^"\(.*\)"$/\1/'`
   PASSWORD=`echo "$USER_PASSWORD" | sed 's/^"\(.*\)"$/\1/'`
   NAS=`echo "$NAS_IP_ADDRESS" | sed 's/^"\(.*\)"$/\1/'`
-#  LOGIN="${User-Name}"
-#  PASSWORD="${User-Password}"
-#  NAS="${NAS-IP-Address}"
 elif [ $# = 3 ]; then
   URL="$1/validate/check"
   LOGIN="$2"
@@ -49,8 +45,10 @@ else
   exit 2
 fi
 
+# Obtain the result using curl
 otpresult=`/usr/bin/curl -s "$URL" --data-urlencode "user=$LOGIN" --data-urlencode "pass=$PASSWORD" --data-urlencode "client=$NAS"`
 
+# Extract the status of the request from the returned JSON
 otpstatus=`echo $otpresult | sed 's/^{.*"result": { "status": true, "value": \(.*\) },.*}/\1/'`
 
 if [ "$otpstatus" = "true" ]; then