Shared services
 
 
- how does a portal know what collections are available?
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- DNER collection description service
 
- how does a portal know how to interact with the service(s) that make a collection available?
- 
- DNER service description service
 
- details not agreed but UDDI, WSDL strong contenders for service description
- also need other shared services
- 
- terminolgy service, metadata registry, user preferences, authentication/authorisation, ...