7.2 Industry and Application-Specific Schema

   The standard schema to be used with the DAF in EMS applications is described in the EPRI Common Information Model chapter. It is fully defined in RDF syntax in [8].

   Additional industry and application-specific schema can be defined in a similar way. Alternatives to RDF syntax may be used provided that the schema unambiguously specifies:

• A unique URI for the schema as a whole, which includes version identification. (Uniqueness may require the inclusion of the Internet domain name of the issuer.)

• Unique URI-references for any conformance blocks and a list of the classes and properties belonging to each conformance block. A conformance block URI-reference may be constructed from the schema URI appended with a fragment identifier. (Note that EPRI CIM version 9a does not define conformance blocks.)

• A unique URI-reference for each class and property that also includes version identification. Again, the URI-reference may be constructed from the schema URI appended with a fragment identifier.

• The domain and range of each property. (Where domain and range indicate the property from and to classes respectively, as per RDF schema.)

• The multiplicity of each property. (Whether it is single or many-valued.)

• The inverse property of each property (if present).

• Any sub-class/super-class relationships.

   Clients can use an industry or application-specific schema in scenarios similar to that shown in Section 3.5, “Query Sequence,? on page 3-15. Since the URI-reference of each class and property is specified, the client simply translates them to ResourceIDs that are used in queries.