4.2.1. Flags

A. Mandatory Flags
Officials are only required to use Yellow, Black and Checkered Flags. At events where passing is allowed, the Blue Flag is also mandatory. It shall be marked in the Supplementary Regulations or explained in the drivers' meetings if the minimal flag set will be used.

1. If the event officials choose to run the minimal flag set, the following multiple-use flag meanings apply:

a. Yellow Flag: Shall be used for Yellow, White and Debris conditions.

b. Black Flag: Shall be used for Black- and Mechanical-Flag situations. The Black Flag may also be used in place of a Red Flag to bring all vehicles to pit lane in an emergency situation.

B. Lights Instead of Flags
Supplemental Regulations will state where on the course and for what purpose lights, if any, will be used.