I noticed it first and thought it was a peice of tape stuck down in his fur if that gives you an idea. Upon further investigation, it seems to be more like a scab on his skin, slightly raised and rough, and the edges seem to "peel up" although I haven't tried to pull anything off of him til I know what it is. Hair seems to grow in the middle of it (thats how I know it's not tape).
Last night I also noticed 2 long thin patches on his back legs, on the bottom by his rear knees. I figured since thats where his legs touch the ground when he's sitting it might be a wear spot, but it wouldn't explain the same thing on his neck in just one area instead of all the way under his collar. His collar also, and all of my kittens, are loose enough to fit 2 fingers under.
Does anyone have any experience with something like this? There is no discoloration in these spots. Looking at them you would think it was a peice of clear tape stuck on his fur.