More about PIDs
A Persistent Identifier (PID) is a unique, long-lasting identifier that unambiguously identifies a digital object, person, organization, research activity, or physical resource. PIDs support the reliable discovery, citation, linking, and reuse of resources over time, even when their location, ownership, or metadata change.
Many PID systems provide resolvable identifiers that direct users to current information about the identified resource. Examples include DOIs for research outputs, ORCIDs for researchers, ROR IDs for organizations, and IGSNs for physical samples. Other identifier systems, such as ISBNs and ISSNs, also provide persistent and standardized identification of publications but do not include a built-in global resolution mechanism.
By enabling persistent identification and interoperability across systems, PIDs play a key role in making research outputs and related entities findable, accessible, and reusable.
RRID (Research Resource Identifier)
Used to identify and cite research materials such as antibodies, cell lines, model organisms, software and databases to improve reproducibility in science. RRIDs are also used for core facilities to ensure proper acknowledgment.
Example: Max Planck Institute of Molecular Cell Biology and Genetics Light Microscopy Core Facility RRID:SCR_023307
RAiD (Research Activity Identifier)
RAiDs track entire research activities and are containers for PIDs describing the components of a project such as researchers, datasets, funding/grants, institutions, and outputs. RAiDs are built on the Handle System infrastructure.
Example: 10378.1/RAiD.987654 (Hypothetical Example)
Resolves via: https://raid.org.au/view/10378.1/RAiD.987654
ARK (Archival Resource Key)
Used for persistent access to digital and physical objects, especially in libraries and archives.
The ARK standard is supported and maintained by the ARK Alliance.
Example: ark:12148/btv1b8449691v/f29
URN (Uniform Resource Name)
A persistent, location-independent identifier, which means it is used to uniquely identify a resource by name, rather than location. Often used in library and government systems. While URNs themselves do not resolve to a resource directly, they can be paired with resolution services.
Example: URN for a document – urn:nbn:de:bsz:21-opus-49771. URNs are part of the larger Uniform Resource Identifier (URI) system, which also includes URLs.
SWHID (Software Heritage Persistent IDentifier)
Used to uniquely and persistently identify software artifacts (files, directories, commits) stored in the Software Heritage archive, enabling long-term reference to source code regardless of where it is hosted.
IGSN (International Generic Sample Number)
Used to uniquely identify physical samples in Earth and environmental sciences, such as rock cores, soil samples, water samples, fossils, or lab specimens, so they can be cited and tracked across studies and databases. IGSNs are governed by the IGSN e.V. and are assigned through DOI-based registration infrastructure.
Example: IGSN:10.58052/SSH000SUA
Which other PIDs are used at MaxIT?
DOI (Digital Object Identifier)
A DOI is a unique and persistent identifier used to reliably reference digital objects such as journal articles, datasets, reports, and other research outputs. DOIs are managed through the DOI System, which ensures that objects remain findable even if their web location changes. If you are interested in DOI assignment via MaxIT, please visit the dedicated DOI page.
Example: https://doi.org/10.17617/1.3
Handle
A handle is a persistent identifier within the Handle System that provides a stable, long-term reference to digital objects. A well-known example of a handle is the DOI. At MaxIT, handles provided by GWDG through the ePIC infrastructure are used in MPG.PuRe (the Max Planck Society’s publication repository). Additionally, MPG researchers can register individual handles for their research objects via the ePIC self-service.
ROR ID (Research Organization Registry Identifier)
ROR IDs are unique identifiers for research organizations worldwide. The Research Organization Registry is an open, community-driven registry designed to uniquely identify institutions such as universities, research centers, and other academic organizations. The Max Planck Society and its institutes are associated with the following active ROR IDs. They are used in our open research data repository Edmond to link researchers to their correct affiliation.
Example: Max Planck Society – https://ror.org/01hhn8329
ORCID (Open Researcher and Contributor ID)
An ORCID is a unique identifier for researchers and authors. It helps distinguish individuals with similar names and ensures proper attribution of their work. MPG.PuRe and Edmond encourage researchers to include their ORCIDs when publishing via these platforms.
Find more resources about Persistent Identifier here:
PID Selection Tools:
Help you explore key PID topics and guide you through the first steps towards choosing the right PID system for your needs.
PID Guide by KB – National Library of the Netherlands
PID Selection Tool by PID4NFDI