I sure have seen it.
The Mustang community is very aware of this sticker. I can't remember what year this coating started in, but it was Ford's attempt to try and reduce the carbon buildup that was happening around the throttle body blade. Many cars were being brought in under warranty with sticking TB's and it was caused by that black soot buildup. Ford came up with this special coating (sorta like McDonalds secret sauce) that was supposed to help. I guess it did some?! Anyway, harsh enough cleaners can strip this coating off and cause a supposed even worse soot buildup than before...go figure?
You should be ok if you didn't go crazy with the cleaners.
When I bought a FRPP 65mm throttle body for my stang, it came with that sticker to stick on the wiring harness to the tb.
Hope this helps,
Ken
