The Dublin Core is a potential model for shareability, from the point of view of its separation of semantics from syntax. Agreeing on the semantics may be more practical for different communities. The goal is not simply to express the present standard in electronic form. Tools for natural language processing may be richer than want can be expressed in a standard thesaurus. The need for use of multiple vocabularies is increasing.
Incompatible relationships cause problems in mapping vocabularies.
A standard representation of a term should be specified, in order to permit normalization. Standard thesauri for companies, products, etc., would be desirable. Desirable relationships may be different for indexers and end users. A standard list of relationships is needed, probably hierarchical, permitting specific types to be mapped to generic relationship types. The AAT has also done some work on types of associative relationships.