The flags Unity uses when it builds acceleration structures associated with geometry used by renderers.
If you set Renderer.rayTracingAccelerationStructureBuildFlagsOverride to true, Unity uses these flags and overrides the default build flags specified when creating a RayTracingAccelerationStructure.
Additional resources: RayTracingAccelerationStructure.Build, RayTracingAccelerationStructure.CullInstances, SystemInfo.supportsRayTracing.