Sanctioning Patches on Boxers Trunks

Anyone know why fighters will have the saction body logo(WBC, WBO) on their trunks. Because not all fighters do it. Like Lewis always had the WBC on, but other fighters like the klitsckos kept their trunks free of patches.

My theory is that the fighter gets some sort of a brake in the sanctioning fees. Why else would some of these big named fighters wear these stupid patches?

....I am not sure why they do it.....You mostly see the WBC logo

A bit of kissing ass never done a fighter any harm ;) people do it every day at their jobs, same for boxers.