Composite flight plan

COMPOSITE FLIGHT PLAN- A flight plan which specifies VFR operation for one portion of flight and IFR for another portion. It is used primarily in military operations.

VFR/IFR or IFR/VFR composite flight plans requires use of FSS to activate and cancel VFR parts.
When VFR, you cannot get an IFR clearance if you are below minimum enroute altitude (MEA) ...