How to model SKA Configurations in a Tango System

This is to provide guidelines on how to manage structured data within the control system.

The Tango device model doesn't support structured data (excepts as Pipes), so we have chosen to use JSON strings as a simple alternative. This choice may be obvious at the moment, but may not seem sensible in the future. Do we support multiple structured formats? Should we use Pipes instead of JSON? Do we define standard ways of mapping between a structured data and flat attribute structure?

The outcome of this can be records in the decision log and updated Control System Guidelines.