A method and system for designating and identifying individual programming that is available in a subscriber television system as a pay-per-view event. The identified programming includes programs that are not normally available for viewing by some subscribers or for which a subscriber has not subscribed....http://www.google.com.hk/patents/US6664984?utm_source=gb-gplus-share專利 US6664984 - Method and system for identification of pay-per-view programming
