<https://www.ip-phone-forum.de/threads/busy-on-busy-je-msn-individuell-einstellbar.310153/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.ip-phone-forum.de/threads/busy-on-busy-je-msn-individuell-einstellbar.310153/>