In the USD you can create Options that you can use within your Actions/Events/etc in the Unified Service Desk Configuration.
You can also access these values from within your own control via C# relatively easily.
To access the value within my USD Custom Hosted Control via C# all that is needed is the following code.
GetConfigurationValue("FoodforThought");
And now I can use this value within the USD without having to create my own configuration files et al in C#.
A follow-up to my post on Getting Started with the Dynamics Web API – on a recent project, I was building a custom hosted control in the USD that leveraged the Dynamics Web API.
However, when I went to deploy my control, my USD instance would implode and not load whatsoever.
Turns out the issue was a result of me using a higher version of the Microsoft.IdentityModel.Clients.ActiveDirectory dll (the latest 3.19) than what is supported in the USD (using 2.22).
The resolution was to downgrade my implementation of this dll to use 2.22 et voila, my solution deployed perfectly and my USD was no longer imploding.
I should note that for the above this is all done using v2 of the USD on a Dynamics 8.2 instance.