Bosch MAF

Hey guys in another thread I was refferred to clean my MAF.. I noticed I had a Bosch MAF and it had a special screw so I couldn't remove, so I took off the whole sleeve. I sprayed with MAF cleaner even though it looked clean, and used a q tip on hot wire.. but on the other side was this brown sticky strip and the qtip hit it by mistake and left a bunch of fibers.. I picked them off the best I could with tweezers, but what is that strip? Is it to tell how old the MAF is? (Like when dirty change?) Just hoping I didn't mess it up getting it touched.. thanks!