Products and Services Code (UNSPSC) and geographic taxonomies. Because a single business may provide a number of services, there may be several Yellow Pages (each describing a service) associated with one White Page (giving general information about the business). Green Pages Green pages are used to describe how to access a Web Service, with information on the service bindings. Some of the information is related to the Web Service - such as the address of the service and the parameters, and references to specifications of interfaces. Other information is not related directly to the Web Service - this includes e-mail, FTP, CORBA and telephone details for the service. Because a Web Service may have multiple bindings (as defined in its WSDL description), a service may have multiple Green Pages, as each binding will need to be accessed differently. UDDI nodes and registry UDDI nodes are servers which support the UDDI specification and belong to a UDDI registry while UDDI registries are collections of one or more nodes. SOAP is an XML-based protocol to exchange messages between a requester and a provider of a Web Service. The provider publishes the WSDL to UDDI and the requester can join to it using SOAP. Federated Discovery The current UDDI search mechanism can only focus on a single search criterion, such as business name, business location, business category, service type by name, business identifier, or discovery URL. In fact, in a business solution, it is very normal to search multiple UDDI registries or WSIL documents and then aggregate the returned result by using filtering and ranking techniques. IBM modularized this federated Web Services Discovery engine in 2001. The released technology from IBM is Business Explorer for Web Services (BE4WS). See also ebXML XML-RPC Java API for XML Registries WS-I Basic Profile United Nations Standard Products and Services Classification (UNSPSC) S-RAMP References External links Research Paper: Investigating Web Services on the World Wide Web, 2008 IBM Article: Aggregate UDDI searches with Business Explorer for Web services, 01 Mar 2002 Research Paper: Discovery of Web Services in a Federated Registry Environment, 2004 Survey Paper: Web Service Discovery Mechanisms: Looking for a Needle in a Haystack?, 2004 Survey Paper:Semantic Web Service matchmakers: state of the art and challenges, 2013 Survey Paper:Cloud service selection: State-of-the-art and future research directions, 2014 UDDI specifications OASIS UDDI Technical Committee UDDI XML.org community site UDDI Browser C++ Data Binding for UDDI Introduction