Networking useProxy Documentation Issue

The documentation regarding useProxy http://docs.unity3d.com/Documentation/ScriptReference/Network-useProxy.html ends with: **"IMPORTANT: You should never enable proxy support for both the server and the client connecting to him. Unexpected things are bound to happen."** However, the code examples that follow in the same page describes using Network.useProxy either just before initialing a server on the host side, or before connecting to the network as client. Can someone explain why? Where is it possible to find a good Networking example with Proxy Server (and possibly Master Server); the community is asking since months and no answer to any post! Thank you