WTTW Prime, WTTWDT2 Channel 1188 is listed as HD but is broadcast in SD.
WTTW Prime, WTTWDT2 Channel 1191 is listed as SD but is broadcast in HD
Comcast is a bit confused right now. WTTW Prime used to be SD-only, but was recently converted to HD when MHz WorldView was added. The regular channel numbers are 370 for downconverted SD and 367 for HD. I think the confusion is that they have two different names. The HD is labeld "PRIME", but the SD is labeled "WTTWP".