Abstract
Persistent unique identifiers (PID) are a critical element in digital research data infrastructure to unambiguously identify, locate, and cite digital representations of a growing range of entities – publications, data, instruments, organizations, funding awards, field programs, and others. The IGSN was developed as the International Geo Sample Number to provide a persistent, globally unique, web resolvable identifier for physical samples. IGSN is both a governance and technical system for assigning globally unique persistent identifiers to physical samples. Even though initially developed for samples in the geosciences, the application of IGSN can be and has already been expanded to other domains that rely on physical samples and collections. This paper describes the current architecture and technical implementation of IGSN, how IGSN relates to other sample identifiers, and how its technical systems are supported by an international governance structure.