Plain Old XML (POX) is a term used to describe basic XML, sometimes mixed in with other, blendable specifications like XML Namespaces, Dublin Core, XInclude and XLink. People typically use the term as a contrast with complicated, multilayered XML specifications like those for Web Services or RDF. The term may have been derived from or inspired by the expression plain old telephone service (a.k.a. POTS) and, similarly Plain Old Java Object. POX is different from REST in that REST refers to a style for communication protocols, while POX only refers to an information format style.