You can now have a reserved TCP port for your account, to run a listening process such as ZNC.
This means other users on barwen.ch are not able to put their own server on the port you were previously listening, if your server processes crashes or has not started up.
To get a port assignment, email firstname.lastname@example.org and ask for one. Your port will be somewhere in the range 512-1023.
When you have your port assignment, you'll need to start your program differently: