YAML with RDA: Resource Description and Access terms.
Any The format uses all terms from rdaregistry.info. Say one were to start a work record, any of the following values could be used as the key to a hash.
http://rdaregistry.info/Elements/c/C10001
http://www.rdaregistry.info/Elements/c/#C10001
"Work"
rdac:Work.en
rdac:C10001
---
rdac:C10001: http://example.org/by/reference
...
A RADML editor would support autocomplete, and a RADML utility would be able to convert between these forms. (Canonical URI, document URL, label, English lexical CURIE, Canonical CURIE).