Thanks for your reply. The reason for the question is simple - I'm planning a flight to Pristina. The previous time I did that was, I guess in 2009 when I unwittingly made the mistake of flying through Serbian airspace on my way out of Kosovo.
The supervisor who notified me of my mistake was very understanding, but I made a mental note about not infringing that procedure again. I have done relatively little flying in that region since then and just thought I'd check whether the limitations were still in place or not.
I guess I could just plan my route around Serbia, not