Enterprise Manager Database Control on host with an underscore in it's name I know it sounds awkward, but Enterprise Manager is refusing to be set up because of an underscore in the server name:

C:\&gt;emca -deconfig dbcontrol db -repos drop

STARTED EMCA um 30.05.2012 13:21:49
EM-Konfigurationsassistent, Version 11.2.0.0.2 Production
Copyright (c) 2003, 2005, Oracle.  All rights reserved. Alle Rechte vorbehalten.

...

SCHWERWIEGEND:  Ungültiger Host-Name vm_scotty11.xxnet.de. Host-Name darf keinen Unterstrich ('_') enthalten.
Weitere Einzelheiten finden Sie in der Log-Datei in c:\app\Administrator\cfgtoollogs\emca\PRJ\emca_2012_05_30_13_21_49.log.
Die Konfiguration konnte nicht abgeschlossen werden. Weitere Einzelheiten finden Sie in der Log-Datei in c:\app\Administrator\cfgtoollogs\emca\PRJ\emca_2012_05_30_13_21_49.log.


Has someone worked around this issue or can provide a documentation link which explains why this happens? 

I know that there must have been warning messages upon installation of OS and DB but I still need to see it written in the docs in order to convince and make the point that the host name has to be changed.
This is happening because an underscore in a hostname is not a valid character according to the RFC.


  "The Internet standards for protocols mandate that component hostname
  labels may contain only the ASCII letters 'a' through 'z' (in a
  case-insensitive manner), the digits '0' through '9', and the hyphen
  ('-')."