1. A method for implementing notifications, the method comprising: storing data defining notification operations in a memory, the data defining notification operations comprising a hierarchy of Uniform Resource Identifiers (URIs) and Extensible Markup Language (XML) document schema defining XML documents; using a processor to: receive a notification command comprising an URI identifying a notification resource and a Hypertext Transfer Protocol (HTTP) GET method; and determine a notification operation based on the data defining notification operations stored in the memory and the notification command received; obtaining a list of notifications indicated in the notification; and returning a NotificationList XML document.