greglook
commented
6 years ago Sets now have a registered tag (number 258) in the IANA registry, so we should use that: https://www.iana.org/assignments/cbor-tags/cbor-tags.xhtml https://github.com/input-output-hk/cbor-sets-spec/blob/master/CBOR_SETS.md
The library currently uses tag code 13 to represent sets of unique elements, but this tag is not registered anywhere. Ideally, it should be added to the IANA registry in the two-byte tag range. This will unfortunately change the canonical serialization of any data using sets, but we can maintain backwards compatibility for some number of future library versions by reading in tag 13 objects as sets if no handler is registered.