How FDO attributes can support machine- and human-readability? - a description along three examples

Based on the notion of a FAIR Digital Object (FDO) record, which consists of key-value pairs as attributes that are precisely defined in a Data Type Registry and selected in a profile, we show three examples of FDOs from different viewpoints how FDO records can be implemented as Handle PID records. As references to the attribute definitions, the keys determine the value space of the attribute. In the first two examples, the profiles enable human-readable keys and legacy digital objects to be integrated into FDO records. How legacy metadata from IANA media types that can be transformed into structured metadata of appropriate attribute definitions that then can be applied in profiles and FDO records, is described in the third example.