[This is preliminary documentation and subject to change.]
Enhancement announcements inform the broadcast client that a show is interactive. Such announcements provide details about the show's enhancements, such as each enhancement's identifier, the show that the enhancement enhances, and the page that contains the enhancement's starting point. An enhancement page is a Hypertext Markup Language (HTML) page; for more information, see Creating an Enhancement Page.
When an enhancement announcement filter receives an enhancement announcement, it stores the enhancement information in the Guide database. The presence of enhancement data in a show listing in the database indicates the show is interactive. Each time that a user tunes WebTV for Windows to a new channel, WebTV for Windows checks the database to see if the new show is interactive. If it is, and the user has enhancements enabled, WebTV for Windows displays the show as interactive.
There are several types of enhancement announcements. For more information, see the following topics:
An announcement can be stored as a text file until it is ready to be broadcast. By convention, the .ann file extension is used for announcement files. For information about how to create these files, see Creating Enhancement Announcements.