Hi, I just want to confirm what was agreed in Boston: The list_services method will be overloaded. To make this look sensible the vo_filter will be moved to the end so we will have: list_services(service_filter, data_filter, vo_filter) and list_services(service_filter, data_filter) Where in the latter case the set of Vos is derived from the context. How do I describe this in the spec - do I describe them as two separate methods that just happen to have the same name or as one method with an optional parameter? SAGA Service types are reverse DNS style. A list of the service types for the services in GFD.90 will appear in the SD specification. Other services in subsidiary packages will define their own service types taking care to avoid any clashes. If you agree I can now get this thing finished off very soon - this week perhaps! Steve