The Main tab contains Beauty, Denoised, and Volume AOV categories. The Other tab contains one AOV for Gaussian Splat scenes. 

BEauty AOVs

Albedo (denoise OIDN) - Outputs the denoised albedo information.

Normal (Denoise OIDN) - Outputs the denoised scene normal information. 

Diffuse - Outputs only the diffuse component of the scene.

Diffuse Filter - Outputs only the non-shaded view of the scene, which are flat regions of the base color or albedo of each material.

Diffuse Direct - Outputs only the single bounce direct of the scene. No indirect contribution.

Diffuse Indirect - Outputs only indirectly-shaded diffuse pixels within the scene.

Reflection -  Outputs only those pixels that receive reflections in the scene.

Reflection Filter - Outputs only those pixels that are receiving reflections in the scene. Output is grayscale. (check this)

Reflection Direct - Outputs only those pixels that are directly reflecting light. No bounce reflections are included in this AOV.

Reflection Indirect - Outputs only those pixels receiving indirect reflections.

Refraction - Outputs any pixels receiving refractions in the scene.

Refraction Filter - Outputs only the unshaded pixels receiving refractions in the scene.

Transmission - Outputs only those pixels that are transmitting light.

Transmission Filter - Outputs only unshaded pixels transmitting light in the scene.

Subsurface Scattering - Outputs only the pixels illuminated by sub-surface scattering.

Emitters - Outputs any light source or light-contributing pixels of the scene. 

Environment - Outputs any visible portion of the environment in the scene.

Denoised AOVs

Denoiser Diffuse Direct - This AOV contains the denoised result of the diffuse direct render pass.

Denoiser Diffuse Indirect - This AOV contains the denoised result of the diffuse indirect render pass.

Denoiser Emission - This AOV contains the denoised result of the emission render pass.

Denoiser Reflection Direct - This AOV contains the denoised result of the reflection direct render pass.

Denoiser Reflection Indirect - This AOV contains the denoised result of the reflection indirect render pass.

Denoiser Remainder - This AOV contains the denoised result of the transmission and sub-surface render passes.

Denoiser Volume - This AOV contains the denoised result of the volume render pass. 

Denoiser Volume Emission - This AOV contains the denoised result of the volume emission render pass.

Volume AOVs

Volume - The volume AOV contains all samples that are scattered in a volume.

Volume Emission - The volume emission AOV contains all of the samples where the camera ray hit a volume emitter.

Volume Mask - The volume mask AOV contains absorption color and the contribution amount of a volume sample. This is a multiplication AOV. To composite volume AOVs, a typical formula would be: (allOtherBeautyPasses)*volume mask + volume + volume emission.

Volume Z-Depth (Back) - The volume z-depth back AOV contains the back depth of all volume samples.

Volume Z-Depth (Front) - The volume z-depth front AOV contains the front depth of all volume samples.