RSS is an XML-based vocabulary for distributing Web content in opt-in feeds. Feeds allow the user to have new content delivered to a computer or mobile device as soon as it is published. A Web site that wants to allow other sites to publish some of its content creates an RSS document and registers the document with an RSS publisher. A user that can read RSS-distributed content can use the content on a different site. Syndicated content can include data such as news feeds, events listings, news stories, headlines.