b. c.
d.
Races which involve a Driver change
Where the Competitor has an ASN approved information system tuned to the frequency of a transmitting device which is under the direct and sole control of the Clerk of the Course or Chief Timekeeper. The system is to be used solely for providing Competitors with timing data issued by the Chief Timekeeper and / or electronic Signals, instructions or warnings issued on the instruction of the Clerk of the Course.
If a frequency used by a Driver / Team / manufacturer / constructor and / or any of their suppliers(‘ Participant’) interferes with a frequency used by a local service or Event Officials or another third party the Participant concerned may be required to change its radio frequency to a non-conflicting frequency to the satisfaction of the Officials of the Event and in accordance with the requirements of Ofcom. The Participant may be suspended from testing and Qualifying and Racing until a change of frequency has been provably effected.
e. Races where Spotters are permitted.
4.13. No signal of any kind may pass between a moving Vehicle and anyone connected with the Vehicle’ s Entrant or Team or Driver save for the following:
a. b. c.
Legible messages on a Pit Board Body movement by the Driver
Verbal communication between a Driver and Team by means of radio using an approved frequency subject to Art. 4.12 above.
d. Lap Trigger Signals as provided below at Arts. 4.14 and 4.15. e. Timing Data in accordance with Art. 4.16 below.
4.14. Lap trigger signals from the Pits to the vehicle: Lap marker transmitters must be battery powered and when operating must be free standing( not attached to any other pit equipment by means of wires or optical fibres) and incapable of receiving external information. Such lap triggers shall use a transmitter operating with a carrier frequency above 10Ghz( radio or optical) and a beam half angle of no more than 36 ° when measured at the 3dB point and shall not be used for the transmission of any data from the pit to the Vehicle other than the lap mark.
4.15. Lap mark data must be transmitted repeatedly and must be demonstrably consistent.
4.16. A single burst of Timing Data from the Vehicle to the Pits as the Vehicle passes the receiver. All timing beacons and receivers must be a minimum of 10m from any official timing beam.
4.17. Mobile phone or tablet devices are prohibited from being carried in the competing Vehicle whilst on the Circuit.
5. Vehicle Competition Numbers and Identification( Ch. 7 App. 10)
5.1. Vehicles will be identified by means of a competition number allocated by the Organisers and displayed as specified in Ch. 7 App. 10. The use of“ 0” or“ 00” is prohibited unless preceded by any number 1 to 9.
5.2. The numbers shall be in position before the vehicle is presented for scrutiny and will be subject to approval as to position legibility and size. Modifications may be required as a result of observations during Practice.
5.3. Competition numbers must be always covered when driving on the Public Highway.
5.4. The Chief Timekeeper may decline to record the performance of any vehicle whose competition numbers are not readily apparent to the Timekeepers.
5.5. On any Vehicle( except Trucks) driven by a person who has not received six Car Race signatures on their Club Licence a yellow square not less than 175mm square with a black diagonal cross with strokes not less than 150mm long and 25mm wide must be visibly positioned on the rear of the Vehicle.
Motorsport UK 2025 National Competition Rules Version 11
Chapter 12 Appendix 4- Organisers’ Regulations and Restrictions 402