"Clearances" in Open FIR
You have declared you are IFR, but the "controlling" authority is providing you with flight information only, being the best they can do in open FIR. No radar service is on offer or indeed available. I accept it would be very sensible to inform the controller of any change in level, (and in so doing potentially other aircraft) but am interested whether you are required to do so because the controller is unable to issue a clearance. I ask the question because I seem to remember a commercial captain with some years to his name getting quite excited about the "common" practise of controllers issuing a direction to aircraft outside their ATZ. For example "XYZ take up a right hand orbit at the VRP, until time z". I would be interested to know who is technically correct, but I do totally accept that in both cases the practice may well help safety and I am not criticising it in principle.