An enhanced television broadcast system may enable the transmission and reception of a real-time event when a new program is about to begin. The real-time event may control access to enhancements from the program that is ending. In some embodiments, these real-time events may constitute triggers that are included within packets transmitted in an Internet Protocol multicast. As one example, the trigger may include a Uniform Resource Locator in the form of a tv: protocol that automatically causes the television display to go to full screen television.