Librarians and repository managers may engage with persistent identifiers in several ways.
Systems
Persistent Identifiers (PIDs) are used in many systems both within libraries and in those used by libraries to identify and aggregate digital objects such as articles and datasets. Many systems which facilitate greater access to resources such as journal articles use a Digital Object Identifier (DOI) as the method to distinguish the resource. For example, Unpaywall harvests Open Access content from a wide range of sources using a DOI.
PIDs are machine readable as well as human readable and unique so are ideal for systems to use. Articles without a PID are much more difficult to track and expose to these different types of services, and in some cases may be excluded from these types of services entirely.
PIDs are also used widely within repositories, the DOI is the metadata element used to provide a link to the version of record of an article from the publishers - a key function of those systems. DOIs are also vital for reporting on research to funders as it will be used as the primary link to journal articles and datasets. The wider infrastructure around DOIs mean that citations can be tracked too. This is critical for assessing impact of publications.
Services from the Library
Working as a librarian or managing a repository you may have reasons to interact directly with persistent identifiers services. For example if your institution is a DataCite customer you may register DOIs on behalf of researchers at your institution, sometimes this is done manually through DataCite’s Fabrica platform or through a repository or Research Information System (RIS) using an API.
Some institutions are also members of Crossref and often it is staff within the library who register content with Crossref. Library staff may also manage the institution’s ORCID membership.
Interacting with Researchers
Research Support or Scholarly Communications Librarians and Repository Managers require knowledge of PIDs as several PIDs form a key part of metadata for resources held in repositories such as DOIs for the version of record of journal articles and ORCIDs to identify researchers. Researchers are also encouraged or event required to assign DOIs for datasets and for this reason an understanding of how persistent identifiers work can be helpful when providing advice and guidance.