Services Registry 
The Services Registry is a UDDI v.3-compliant services registry for Web services that is located centrally within an SOA landscape. It extends the UDDI standard by providing convenient access to UDDI entities and introducing additional classifications that enhance SAP's Enterprise Services concept. The Services Registry contains information about services provided in that landscape, with references to the WSDL metadata relevant for those services and to the locations of the callable service endpoints.
You can use the Services Registry to publish Web services, manage your classification systems, search for and find Web services for consumption, and test your Web services.
Accessing the Services Registry
Users can access the Services Registry through a user interface or via an application programming interface. The Services Registry is integrated with the development environments and user interface tools of the AS Java, so that you can search directly for service definitions from the development environment to create a consumer application. Furthermore, you can browse the Services Registry from Microsoft Visual Studio using SAP Enterprise Services Explorer for Microsoft .NET.
Publishing Services
Users can publish services into the Services Registry using the corresponding tools available in the development infrastructures:
Publish activated service interfaces from Enterprise Services Repository.
Publish sender agreements from Integration Directory.
Publish implemented and configured ABAP or Java service definitions from AS ABAP or AS Java, respectively.
Publish and classify third party service definitions in the Services Registry's user interface by entering the WSDL of a service definition.
Publish services from out of Microsoft Visual Studio using SAP Enterprise Services Explorer for Microsoft .NET.
Classifying Services
When you store a lot of entities in a productive registry, you can use classifications to structure these data sets. To support classification and browsing in the user interfaces, Services Registry provides an additional classification service that enhances the UDDI standard. This service provides the user interface with metadata on different classification systems, and the content of each classification system. The classification systems delivered as part of the Services Registry include, for example, Deployment Unit, Process Component, Business Object, Service Interface, Extended By Industry, and Organization Name.
You can classify services in the Enterprise Services Repository and in the ABAP and Java development environment. The classifications assigned to a service are published along with the service definition. You can also classify services directly in the Services Registry. This is useful for non-SAP services that have been published without classifications to the registry.
The Service Registry allows the management of classification. You can create new classifications, can create new values for existing classifications, or edit existing values. You can then use these classifications and values for classifying your services.
Discovering Services in the Services Registry
The Services Registry is the central entry point for service consumers. Each consumption tool implements the Services Registry to find the needed entities. It uses the reference provided by the Services Registry to retrieve the concrete metadata from a separate location.
To find a service to use, the consumer queries the Services Registry in one of the following ways:
The consumer can search or browse the Services Registry by classifications to find available service definitions.
The search is based on classification groups and the physical systems where these services are located.
The consumer can search or browse the Services Registry by classifications to find service groups.
The search is based on the service group name and classification groups.
In reply, the Services Registry delivers the reference to the metadata. The consumer/consumption tool retrieves the metadata using this reference from the Enterprise Services Repository (for modeled design time entities) or from back-end systems (for service definitions and service endpoints).