Did you know that if you receive a “hold for release” IFR clearance at an uncontrolled airfield then decide to depart VFR to pick up your clearance in the air it is a violation? A “hold for release” clearance is just what it says it is, a clearance, and as such you are not authorized to depart without first canceling either your IFR flight plan or clearance. After, though, you can depart VFR and then pick up your IFR clearance in the air if it is still active.
The above is intended to be advisory in nature and does not supersede any information contained in the FAR’s or AIM. Every situation is different and may not apply to every flight.