External References to Values in CBOR Diagnostic Notation (EDN)

The Concise Binary Object Representation (CBOR, RFC 8949) is a data format whose design goals include the possibility of extremely small code size, fairly small message size, and extensibility without the need for version negotiation. CBOR diagnostic notation (EDN) is widely used to represent CBOR data items in a way that is accessible to humans, for instance for examples in a specification. At the time of writing, EDN did not provide mechanisms for composition of such examples from multiple components or sources. This document uses EDN application extensions to provide two such mechanisms, both of which insert an imported data item into the data item being described in EDN: The e'' application extension provides a way to import data items, particularly constant values, from a CDDL model (which itself has ways to provide composition). The ref'' application extension provides a way to import data items that are described in EDN.