to expand on Spitton's paragon of brevity!!
on leaving Class A airspace you can cancel an IFR flight - AIP ENR 1-10-7 1.10.1 refers.
You can also specify your intentions in the flight rule field (field 8) by using a 'Y' for IFR followed by VFR or a 'Z' for VFR followed by IFR and stating VFR at the appropriate point in the route (field 15)
However note the caveat in AIP ENR 1-10-5 3.2.2 concerning the way the integrated flight plan processing system (IFPS) handles only the IFR part of the plan, and note that the plan must be fully addressed to get the benefit of 'flight following' and possible overdue action during the VFR part of the route.
Phew!
Tori
