Anyone ever see this on their airbox.

"Says when changing the oil, you are not suppose to have the dipstick out while filling with oil"

I never saw that sticker before on my previous model.

I always take my dipstick out and clean it when removing the oil. I insert it when the I put fresh oil in.

What harm does it do to not have the dipstick in when filling?

 

I read that too, but wasn't too sure about the rationale. So I just leave it in until I've poured in the 5 qts.

 

I might be (?) vented to the head. If so, when you add oil it could leak out. I'm not gonna try it though.