This setting does not apply to desktop apps.
A pipe-separated list of domain cloud resources. Each cloud resource can also be paired optionally with an internal proxy server by using a trailing comma followed by the proxy address.
Contains a list of Enterprise resource domains hosted in the cloud. Connections to these resources are considered connections to enterprise networks.
If a proxy is paired with a cloud resource, traffic to the cloud resource will be routed through the enterprise network via the denoted proxy server (on Port 80). A proxy server used for this purpose must also be configured using the Intranet proxy servers for apps policy.
For more information see: http://go.microsoft.com/fwlink/p/?LinkId=234043