The host makes you sign a separate agreement that is outside of what AirBnb makes you do. I've never had to do this before.
The host also only provided 2 keys to the unit. Because of this, somebody had to ring the doorbell (pretty early in the morning) to get back into the unit. She refused to let us in without paying her $150. Even after agreeing to pay her $150, it was a struggle for her to allow us back into our airbnb.