When this flag is set, Unity performs occlusion culling as part of the culling operation.
Default value: set if the Camera from which you obtained the CullingParameters object has Camera.useOcclusionCulling set to true. Otherwise, unset.
Additional resources: Camera.useOcclusionCulling, Occlusion culling, ScriptableCullingParameters.cullingOptions, ScriptableRenderContext.Cull, CullingResults.