4000,11,KCNC
4001,11,KMGH
4002,11,KUSA
4003,11,KXAS
4004,11,WBBM
4005,11,WFAA
They seem to be phantom channels.
There are EPG entries in the EPG stream for all six of them with complete program listings.
Years ago, I had contact with someone who actually had these showup in the EPG on a 5000 receiver. It was a one-time occurance.