that is correct... though, I'm sure if you have 8 people in your room at 4 in the morning and someone next to you complains to the front desk, they could excersize the right to kick you or the people out of the room. that would be up to the hotel.
but to my knowledge, there is no problem with having people visit your room... they just don't want to see two beds used, a roll away, and then 3 sleeping bags on the ground (which could indicate either 6 people, or 8, dpending on how friendly those people are).