Seems like a strange transmission. Are you sure they said "IFR"?
Being asked what service you require would suggest that you are about to leave CAS and therefore will no longer be under a Radar Control Service. The controller was asking you what service you would like outside CAS, i.e. Basic, Traffic, or Deconfliction Service.
Last edited by Glamdring; 4th Sep 2012 at 10:13.