This publication includes the metadata schema and documentation for the registration of International Generic Sample Numbers (IGSN) by GFZ Data Services between 2015 and 2024.
The IGSN schema definitions included here give an overview of the existing elements for sample description used in the different data centres managed by the IGSN Agent GFZ Data Services. To date, GFZ Data Services organises their IGSN collections according to different projects or research groups which are displayed as different datacentres in the catalogue (https://dataservices.gfz-potsdam.de/igsn-new/).
The modular IGSN metadata schema, developed by IGSN e.V., formed the basis for the registration of IGSN sample descriptions. Until 2022, the following three modules were used:

IGSN Registration Metadata Schema: mandatory metadata properties required for the IGSN registration (Handle Server)

IGSN Descriptive Metadata Schema: generic description of a specimen’s core elements as defined by IGSN e.V. These elements were intended to represent the common metadata kernel for all IGSN allocating agents.

IGSN Supplemental Metadata Schema: additional, sample-specific metadata elements that can be individually developed by IGSN Allocating Agents.

This schema represents a further development of the IGSN metadata schema originally developed by System for Earth Sample Registration (SESAR², www.geosamples.org) in the framework of the IGSN Organisation (IGSN e.V.) with specific additions for the GFZ use case. It was used for IGSN registrations since 2015.

As part of the project "FAIR Workflows to establish IGSN for Samples in the Helmholtz Association" (FAIR WISH), funded by the Initiative and Networking Fund of the Helmholtz Association (Helmholtz Metadata Collaboration HMC). these schemes were secured and the documentation for the registration metadata, descriptive metadata documentation was completed.

The International Generic Sample Number (IGSN, www.igsn.org) is a globally unique, resolving, and persistent identifier (PID) for physical samples/specimens with a dedicated metadata schema supporting discovery functionality in the internet. IGSNs enable to directly link data and publications with the samples they originate from and inform about the whereabout of a specific sample. IGSNs were developed and used in the geosciences domain and are governed by an international non-profit organisation (IGSN e.V.) which also operated the central registration system based on the Handle.Net system until December 2022. In recent years, the potential application of IGSNs for physical objects/ specimen is also explored beyond the geosciences (e.g. archaeology, material sciences).

IGSNs resolve via a persistent link to IGSN landing pages with a digital sample description, managed by federated IGSN allocating agents (Klump et al., 2021). GFZ is a founding member of IGSN e.V, and has been an active IGSN allocating agent for, e.g., samples of scientific drilling projects in the framework of the International Continental Scientific Drilling Program (ICDP) since 2015 (Conze et al., 2017).

The IGSN metadata schema of GFZ was initially aligned with that already in use by the System for Earth Sample Registration (SESAR², www.geosamples.org), the largest IGSN registering agency, and was only extended for specific cases, like, e.g., drilling methods. For later projects, some new metadata elements were added when required. The aim for this strategy was to be as harmonised as possible across IGSN allocating agents and facilitate search options in the planned global IGSN catalogue. The IGSN metadata schema is described in more detail in the following subsection.

In October 2021, the IGSN e.V. and DataCite announced their strategic partnership (Buys and Lehnert, 2021). This induced a major change in the registration of IGSNs as they have to be registered as DataCite DOIs (IGSN IDs) since January 2023.