Identifying custom Collision Channels

When you add a custom collision channel it can be either 1.A trace channel or 2. An Object channel

When you want to use the channel in C++ how do you identify which channel is Object and which is Trace?

The ECollisionChannel enum defines ECC_GameTraceChannel1-18 and ECC_EngineTraceChannel1-6 but nothing like ECC_GameObjectChannel.

So how do you use a custom object channel?