A metadata push technology, i.e., a technology that can identify changes in data and initiate a content push to the end user, without the user having to search it out and pull it from the site.The term RSS is an umbrella term variously used to describe a number of versions of several data Web feed formats specified in Extensible Markup Language (XML) and used for syndication of Web content. Those standards include Really Simple Syndication, Rich Site Summary, and RDF Site Summary. More recently, the IETF adopted the Atom Publishing Protocol (APP), which builds on the previous RSS work.The Atom Syndication Format is described in IETF RFC 4287 (2005). See also metadata, push, Web, and XML.