diff --git a/materials.py b/materials.py
index 679b1fa..450de8c 100644
--- a/materials.py
+++ b/materials.py
@@ -1,13 +1,26 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-# -*- mode: python-mode; python-indent-offset: 2; tab-width: 2 -*-
+"""\
+Material database.
 """
-Created on Mon Dec 21 19:39:44 2015
+__author__ = "Daniel Weschke"
+__copyright__ = "Copyright 2019 Daniel Weschke"
+__credits__ = ["Daniel Weschke"]
+__license__ = "MIT"
+__version__ = "2019.02.03"
+__maintainer__ = "Daniel Weschke"
+__email__ = "daniel.weschke@directbox.de"
+__status__ = "Production"  # "Prototype", "Development", "Production"
 
-@author: Daniel
+VERSION = """\
+%(prog)s version {version} {copyright}
+""".format(
+  version=__version__, copyright=__copyright__)
+
+EPILOG = """\
 """
-import sys, os
-import argparse
+
+import os
 
 
 def list():
@@ -22,7 +35,7 @@ def list():
 def read(input, search_keys=None):
   import json
   from pprint import pprint
-  
+
   def find_values(id, json_repr):
     results = []
 
@@ -44,7 +57,7 @@ def read(input, search_keys=None):
           for value in found_values:
             #print('%-5s' % value[0] + ' ' + value[1])
             print(search_key + ' = ' + '%s' % value[0] + ' ' + value[1])
-          
+
         #def getLength(element):
         #  try:
         #    element.__iter__
@@ -53,7 +66,7 @@ def read(input, search_keys=None):
         #    return 1
         #print(len(data))
         #print(getLength(json.loads(data)))
-        
+
       else:
         data = json.load(data_file)
         pprint(data)
@@ -65,41 +78,55 @@ def read(input, search_keys=None):
 
 
 def main():
-  parser = argparse.ArgumentParser(description='Material database.')
+  """\
+  Main function
+  """
+  import argparse
+
+  parser = argparse.ArgumentParser(
+    description=__doc__, prefix_chars='-', epilog=EPILOG,
+    #usage="%(prog)s [OPTION]... NAME",
+    formatter_class=argparse.RawTextHelpFormatter,
+  )
+  parser.add_argument('-v', '--verbose', action="store_true", help="Verbose output")
+  parser.add_argument('-V', '--version', action='version', version=VERSION)
+  parser.add_argument('-D', '--debug', dest='debug', action='store_true', help=argparse.SUPPRESS)
 
   subparsers = parser.add_subparsers(help='commands', dest='command')
 
   # list materials
-  list_parser = subparsers.add_parser('list',
+  parser_list = subparsers.add_parser('list',
                                       description='List materials.',
                                       help='list all available materials')
 
   # material
-  material_parser = subparsers.add_parser('material',
-                                   help='the material to get information from')
-  material_parser.add_argument('materialname', action='store',
+  parser_material = subparsers.add_parser('material',
+                                          help='the material to get information from')
+  parser_material.add_argument('materialname', action='store',
                                help='list available material information')
-  material_parser.add_argument('-r', '--rho', dest='const_collection',
+  parser_material.add_argument('-r', '--rho', dest='const_collection',
                                action='append_const', const="rho",
                                help='get density from material')
-  material_parser.add_argument('-T', '--Tm', dest='const_collection',
+  parser_material.add_argument('-T', '--Tm', dest='const_collection',
                                action='append_const', const="Tm",
                                help='get melting point temperature')
 
-  parser.add_argument('-v', '--version', action='version',
-                      version='%(prog)s 1.0')
-
   args = parser.parse_args()
-  print(args)
+
+  if args.debug:
+    print(args)
+
   if args.command == 'list':
     list()
+
   elif args.command == 'material':
     if args.const_collection:
       read(args.materialname, search_keys=args.const_collection)
     else:
       read(args.materialname)
 
+  return 0
 
 if __name__ == "__main__":
-  main()
-
+  import sys
+  sys.exit(main())