Two points related to the thread by unrelated to each other -

1) No one seems to have any problem using special discount codes for car rentals that are special contract rates for corporations or organizations. Is there some inherent difference?

2) There is a potential problem using hotel meeting rates if you book through a conference site. There is often a separate check-in table other than the front desk set up for conference attendees. Hotel guests attending such a conference often pick up there room key as well as their conference material at such a desk. What will happen if you go to pick up your room key but are not registered for the conference?