PIDfest 2026: Persistent Identifiers at the Heart of Research Infrastructures

From 27 to 29 October 2026, the second edition of PIDfest, an international event dedicated to persistent identifiers (PIDs), took place at the Naturalis museum in Leiden, the Netherlands. Organised by SURF, a Dutch organisation dedicated to digital services for higher education and research, and DANS (Data Archiving and Networked Services), this event followed on from the first edition, hosted in 2024 in Prague by the National Technical Library of the Czech Republic (NTK).

The event brought together numerous stakeholders from the international ecosystem of persistent identifiers to discuss technical developments, their uses in research, and the challenges relating to their governance and funding.

An ever-evolving ecosystem of identifiers

A significant part of the programme was devoted to identifiers associated with the DOI (Digital Object Identifiers) ecosystem, featuring presentations by Crossref, ROR (Research Organisation Registry), ORCID (Open Researcher and Contributor ID) and ARDC (Australian Research Data Commons), which is developing the RAID (Research Activity Identifier).

These presentations provided an opportunity to assess the progress made in linking identifiers and research infrastructures. They also highlighted the value of continuing dialogue between the various communities in order to foster a broader and more complementary approach to identification systems.

Artificial intelligence featured prominently in the discussions. Several speakers emphasised that AI tools do not yet take sufficient account of the persistent identifiers used in scientific research. Meanwhile, representatives from Crossref and ROR outlined the opportunities offered by these technologies to improve the quality, consistency and enrichment of metadata.

The long-term financial sustainability of infrastructures: a shared challenge

Representatives from the NTK presented the activities of their National Centre for Persistent Identifiers, which receives funding under the CARDS (Czech Academic and Research Discovery Services) project, supported by the European Johannes Amos Comenius Operational Programme for the period 2023–2028. This initiative supports the development and adoption of persistent identifiers within the Czech research ecosystem, complementing national initiatives linked to the EOSC (European Open Science Cloud).

The speakers discussed, in particular, the use of identifiers by Czech research institutions and research information systems (Current Research Information Systems, CRIS). They also presented ePIC (Persistent Identifier Consortium for eResearch), a persistent identifier infrastructure based on Handle technology, which enables the long-term identification of various types of digital objects, including datasets, documents and research samples.

Discussions centred on the prospects for funding activities beyond 2028, highlighting the importance of sustainable resources to ensure the continuity of services. This concern was also expressed by representatives of RAID, whose current funding is set to exp ly in 2028.

These discussions serve as a reminder that the sustainability of persistent identifiers depends not only on reliable technical solutions, but also on economic models and governance mechanisms capable of ensuring their long-term maintenance. The NTK will also host the 52nd meeting of the directors of the National ISSN Centres in Prague in October 2027.

ARK identifiers and the importance of link maintenance

Several presentations focused on ARK (Archival Resource Key) identifiers, which enable the long-term identification of digital and heritage resources. The Royal Library of Belgium (KBR) presented its work on implementing these identifiers for its digitised collections and archives.

In France, these identifiers are used in particular by the Bibliothèque nationale de France (BnF) to ensure the long-term identification of its digital resources and bibliographic records. The Bibliographic Agency for Higher Education (Abes) also utilises the ARK identifiers assigned by the BnF to strengthen the interconnection between records in Sudoc and those in the BnF’s General Catalogue, particularly for serial publications. The use of this identification system is also among the options being considered in national initiatives on the permanent identification of research organisations.

John Kunze, the founder of the ARK system, led a workshop on the fundamental principles of persistent identifiers. In particular, he emphasised that no identification system can, on its own, guarantee the permanent availability of a digital resource. The stability of identifiers depends, in fact, on the maintenance of links and the updating of the addresses to which they redirect.

This observation highlights the importance of actively managing identification infrastructures, which is essential for ensuring continuous access to resources. ARK’s decentralised model, which relies on naming agencies, is also of particular interest in a context where issues of digital sovereignty, data control and the autonomy of research infrastructures are playing an increasingly significant role in public policy.

Metadata quality and identifier reliability

The presentations on ROR provided an opportunity to review the origins and development of this international register of research organisations, which was initially compiled using data from the GRID (Global Research Identifier Database) register.

One workshop, in particular, addressed methods for improving its metadata, combining contributions from the organisations concerned, validation procedures and artificial intelligence tools. The discussions also highlighted the difficulties faced by identifier managers when dealing with requests from organisations whose status or scientific activities require in-depth verification.

These situations underscore the importance of transparent and rigorous procedures to maintain trust in identifier registries. The assignment of an identifier cannot, in itself, constitute recognition of an organisation’s scientific quality or institutional legitimacy.

Towards more inclusive national identifier strategies

Several countries, notably France and Germany, are gradually developing national strategies for persistent identifiers in research. These initiatives represent a significant step forward in strengthening the interoperability of information systems, facilitating the circulation of metadata and improving the visibility of research results.

It is nevertheless essential that these strategies take into account the full range of identifiers that underpin the scientific information ecosystem, going beyond those most frequently used in research infrastructures.

In this regard, the ISSN (International Standard Serial Number) and the ISBN (International Standard Book Number) play a role that complements that of other persistent identifiers. They contribute to the reliable identification of scientific publications and to the interlinking of bibliographic data with other components of the research ecosystem.

The ISSN International Centre wishes to encourage greater consideration of these complementary aspects in national and international strategies relating to persistent identifiers. Through its network of National Centres, it intends to continue the dialogue with research stakeholders, standardisation bodies and digital infrastructure managers in order to promote an open, interoperable and sustainable approach to the identification of scientific resources.

Participation in PIDfest 2026 thus provided a unique opportunity to strengthen exchanges with other identifier communities and to highlight the ISSN network’s vital contribution to the reliability and longevity of scientific information.