IGSN IDs are registered with metadata encoded in the DataCite Metadata Schema. The following guidance for IGSN ID metadata in the DataCite Metadata Schema was developed by the IGSN–DataCite Crosswalk and Metadata Management Working Group and sourced from the IGSN–DataCite Crosswalk Recommendation. DataCite, the IGSN e.V., and the Working Group will continue to expand and refine metadata best practices for IGSN IDs over time.
The current guidelines for IGSN ID metadata are outlined here: https://support.datacite.org/docs/igsn-id-metadata-recommendations.