>In this case, the client specifically asked for flashing. It's too long ago for me to remember when I pushed them on it or not. But the key point is that it's used briefly and specifically to draw attention to an individual item. It's also a very small area that flashes.

I've seen an area of about 120x400px flash nastily for about three seconds when a patient record is brought up, and that's only in the cases when patient has a serious allergy. The flashing area contains the warnings of this kind. And for this kind of exception I don't mind breaking the rules.