Did you look at the register example app in the SDK? It' a rendezvous linking implementation and does show typical requests and responses you app would make with your server.
The example uses static XML files on the server, but in your server implementation you would create similar dynamic XML as the responses. You would use whatever language you wanted to do this (PHP, Java, C#...) and the code would be custom to every developer as you would need to integrate with your authorization scheme and connect to tables in your schema.
The other sources of info in the docs are the DeviceRegistrationAndLinking guide and the roCodeRegistrationScreen documentation in section 4.12 of the Component Reference.
--Kevin
