The following definitions and abbreviations are adopted for use in this rulebook.

AGE CLASS A rider's classification with respect to his or her age.
AFTERMARKET Manufactured or fabricated by other than the original manufacturer.
ARENACROSS An Arenacross is conducted within an arena-type facility on a specially-constructed flat race track. Track design is similar to Supercross but much shorter in length and a little narrower due to the smaller area.
CC Cubic centimeters.
DISPLACEMNET The space covered volume swept out by the piston at each stroke.
DISQUALIFICATION The forfeiture of all awards, prizes, monies and points earned in all events during that day's meet.
DOT Department of Transportation
EVENT A competition at which one or more races are held.
HEAT RACE A qualifying moto that determines which riders advance to the final.
MMRS Maguire's Motocross Racing Series.
MODEL A reference to a particular year and name assigned by manufacturers to certain motorcycles.
MOTO One half of a race at an event.
MOTOCROSS Motocross is motorcycle competition conducted on an off road closed course and must be a minimum of half mile in length with a maximum of two miles in length. The course should be irregular so that both right and left hand turns have to be negotiated. It is advisable to include hills, jumps and other terrain that necessitates gear changing. Natural terrain should be used wherever possible. Tracks should try to maintain a 30-foot width but at no time should they be narrower than 16 feet.
MOTORCYCLE A motorized, two-wheeled, competition vehicle identified by its engine, frame number, frame tag or other frame marking.
OEM Original Equipment Manufacturer.
OFFICIAL (With reference to race results) - A listing of the final finishing order of an event issued by scoring after the 30-minute protest period has expired.
PADDOCKS or PITS Designated area primarily used for maintenance of event-entered competition motorcycles and parking area for motorcycle transport and support vehicles.
PARTICIPANT Every club, association, company, promoter, rider and all other persons participating or in any way connected with a MMRS race meet.
PIT CREW or CREW Mechanic and/or assistants.
PROGRAM The predetermined outline of moto's that make up an event.
PRIMARY CLASS A rider's classification with respect to his or her ability
PROVISIONAL (With reference to race results) - An initial listing of the finishing order of an event issued by scoring immediately following the race finish. The posting of provisional results begins the 30-minute protest period.
PROMOTOR Any person or number of persons, company, corporation or club holding, proposing to hold, or organizing a meet.
QUALIFY To advance to a final event by timed qualifying or heat race finish position.
QUALIFIER / CONSOLATION A qualifying moto that transfers riders to a main event.
QUALIFYING MOTO A preliminary race that may be used for elimination or to determine moto starting positions.
RACE Two motos of a class at an event, in which three or more riders compete against each other.
RACE TRACK These will include the actual racing surface and runoff areas, the pit road and grid, a test track when provided and any other area where the riding of a competition motorcycle is permitted.
RIDER Any person who competes on track in a meet.
STAGING The area where riders wait before being called to take their position on the starting line.
STARTING LINE A pre-designed area where all riders line up beside each other to start their moto.
SUPERCROSS Supercross is conducted within a stadium-type facility on a specially- constructed flat race track. The racetrack generally should be 20 feet in width at its narrowest point.
SUSPENSION (With reference to penalties) The loss of all rights to compete as a rider or member of a pit crew for the stated period.
TECHNICAL INSPECTOR The technician who inspects all motorcycles and equipment of riders participating in a meet.