A SOAP binding is similar to an interface for XML Web services. It is useful for versioning and when you look for a XML Web service implementing a specific SOAP binding. For instance, a discovery document might contain optional information about SOAP bindings, which specify the SOAP bindings implemented by referenced Web Servcies. SOAP bindings are specified within the XML document containd within a discovery document by adding a SOAP XML element with an XML namespace equal to the SoapBinding.Namespace constant. The SoapBinding.Address property specifies the URL of the XML Web service and the SoapBinding.Binding property specifies the SOAP binding implemented by that XML Web service.