The agency I worked for had reserves who were fully trained (been through the FTO program) and would fill in for officers who were on vacation, sick, and work special events (Bike Week, Biketoberfest, Arts Festivals, parades, football games, races, etc.) Some of the neighboring jurisdictions that had reserves only used them for prisoner transport, courtroom security, or walk-in complaints. Our reserves would come in check out a vehicle, radio, long gun, and then be assigned a zone just like the full-time officers. But it does depend on the agencies needs.