With light IDs set in the emitter nodes, you can exclude them by material in object layers, and also globally in the kernel settings. Octane has 8 light IDs, and you can also choose whether to enable the sun and environment separately.
Given a base scene with a number of emitters:
Figure 1: A basic scene with a number of emitters
Figure 2: Users can suppress the highlight of the emitter on selected spheres, while keeping the ground lighting and shadows resulting from the extra emitter
Light Linking And Light Exclusion settings are found under the Light section in the Kernel Settings (Figure 3).
Figure 3: Light Linking and Light Exclusion controls are accessed via the Light section of the Kernel settings.
Light ID Action (Action to be taken on selected light IDs)
Light IDs (Light ID specified)
Light Linking Invert
These are used by Light Linking and Light Exclusion features for Emitter Nodes. Light IDs can also be enabled/disabled globally in the Kernel Settings. The Light Linking Invert option will invert the light linking behavior for selected light IDs.
Global Light Exclusion
With the same light IDs used by light linking, you can enable or disable the light IDs globally through the Kernel Settings.