[Observium] What's the secret

Hello,

I have been messing with Observium off and on for the last month. I noticed one of my devices is showing up under Ports > Customer

Only thing I can find different for this interface is the desc has CUST: at beginning of the description.

I can't find any docs on this feature.. Any someone point me in the right direction.. How to get all customer ports showing up?

Thanks. Sonny