Anyone who wishes to "release" books, whether leaving it in a public place or passing it on to a friend, must register on the BookCrossing.com website, although there is the option to remain hidden when "catching" the find of a book. BookCrossing.com users can 'go hunting', where a member will go to the website to view a list of books that have just been "released", then go to the place it was left to "catch" it. Books may also be left at Official BookCrossing Zones" (OBCZs), which are located in certain coffee shops, cafes, restaurants and other public places. The purpose of these places is to get members in the area to leave books to share with the public. This also promotes BookCrossing and creates more members.