A permissive operator is a driver that has been given permission to operate a vehicle.
Typically, if you do not give someone permission to drive your vehicle then the insurance coverage may be nullified or changed. An insurance company cannot be liable for those unknowns, so that is why they only offer coverage for permissive operators in most instances.
Permissive operator coverage is not included in a non-owners policy since this type of insurance only covers the policy holder. There is no permission that could be given, because it is a non-owners policy and not tied to an insurable interest (vehicle).