Controlled Vocabularies
RDA has many controlled vocabularies. Only a few of the vocabularies are closed (e.g., content type; media type; carrier type; mode of issuance). Most of the vocabularies are open; you can either supply your own term as needed, or suggest a term be added to the vocabulary (or do both).
Libraries may decide to include some of these controlled vocabulary terms in templates; ILS vendors could provide them in drop-down lists. And so on.
The RDA vocabularies are now registered on the Web. The existence of those machine-readable controlled vocabularies will allow more machine manipulation of data than is now possible, including the mapping of RDA to other metadata schemes.