Say Again
A RAS is the only way pilots in Class G airspace can be given info necessary to resolve any confliction (avoiding action).
Pilots request a RAS, the controller doesn't necessarily know if the pilot is not IMC rated because the service is always provided as if the flight is an IFR flight.
If the controller gives the pilot an instruction (service is advisory but advice is given in the form of an instruction) that requires flight in IMC, the pilot is responsible for saying he can't take the manoeuvre. The service is then downgrade to a RIS and only traffic info is passed from then on in. Or, put another way, the pilot is thrown to the dogs.
In essence, it's the only way a flight being conducted in VMC in Class F and G airspace can be given instructions to resolve a confliction.
The Greebs