I have a question regarding the Galileo inventory codes pulled through the "German" connection sites like seatmap.com

I have a suspicion that CO/NW are holding alot of seats out of the lower fare buckets (and blocking alot of seats in coach) on the 21 and 14 day advance fares until those fares about to go out of their purchase windows. When I do an inventory search on Galileo, instead of seeing codes like "V0" and "K0", I see "KC" and "VC" for the flights I want to take. Other flights might show "0"s for certain fare classes, but only some show "C".

My question is first, has anyone encountered this before, and second, could the "C" code beside the fare bucket stand for "capacity" or something to indicate the bucket is not sold out, but is being held for revenue control. If I search for my flights 4-6 weeks out, they show as sold out at all the lower fares (unlikely, given the loads I usually see)...but when I run a fare search two weeks out, the lower fares appear. It's abit frustrating because I want to book well in advance, but I dont want to pay $300 for something I can pay $180 for two weeks later.