I wonder if anyone could help me.

Does anyone know the regulations with expanding flash banners?

Like what would i call the size..

for example check out : http://uk.yahoo.com

See on the right it says Mail, Weather, Messenger etc etc.

When you hover over that it expands, but would i call the image size the size it expands into.

Like, would it be 468x60 OR 468x150.

I hope someone can help!