FAIR Metric - F1 - Metadata - Identifier is persistent

This metric evaluates whether the identifier provided as input satisfies the EOSC-PID aligned [FAIRsharing definition](https://fairsharing.gitbook.io/fairsharing/record-sections-and-fields/general-information/globally-unique-persistent-and-resolvable-identifier-schemas) of persistence.

F1 requires that metadata be assigned a globally unique, persistent and resolvable identifier. This metric is particularly concerned with the persistence aspect of GUPRIs; persistence is required to guarantee long-term continuity of reference. Without persistence, identifiers may break, change or be reassigned, undermining citation, traceability and reproducibility. In this metric, the definition of persistence follows the [FAIRsharing guidance](https://fairsharing.gitbook.io/fairsharing/record-sections-and-fields/general-information/globally-unique-persistent-and-resolvable-identifier-schemas) on Globally Unique, Persistent and Resolvable Identifier (GUPRI) schemas. This definition requires that the identifier schema must have clear community backing for the schema and its long-term maintenance. The syntax of the schema must be stable, and the referred object should itself should also be stable, though there are various ways to show this (e.g., a dataset might be completely immutable, while a record describing an organisation is likely to change as the organisations homepage, name or other attributes change). This metric evaluates whether the identifier provided as input is issued under a schema that meets the FAIRsharing definition of persistence. The evaluation assesses whether the identifier schema demonstrates documented long-term maintenance and governance consistent with these criteria.

For an in-depth understanding of the issues around identifiers, please see [http://dx.plos.org/10.1371/journal.pbio.2001414](http://dx.plos.org/10.1371/journal.pbio.2001414). #