EFR rating: When VFR rating is not anough and IFR rating is too much.

[martymayes]

Pilots fly VFR and they follow the VFR rules, pilots fly IFR and they follow the IFR rules, pilots fly VFR OTT and they follow the VFR OTT rules.

In the US, there are no VFR over-the-top rules. The FAA would prefer VFR only pilots not fly VFR OTT but it's not illegal. The US does have VFR on top which is done on an IFR clearance.