For players who use the Unreal server browser: Add this line to your Unreal.ini file. In the [UBrowserAll] section:

=======================
ListFactories[1]=UBrowser.UBrowserGSpyFact,MasterServerAddress=master.hypercoop.tk,MasterServerTCPPort=28900,GameName=unreal
=======================

You should add this line below the ListFactories[0]= line.

For individuals or organisations who run Unreal servers:
Add this line to you server's Unreal.ini. In the [Engine.GameEngine] section:

=======================
ServerActors=IpServer.UdpServerUplink MasterServerAddress=master.hypercoop.tk MasterServerPort=27900
=======================