6 Association of Research Libraries Research Library Issues 302 — 2021 the services that support them, can enable the discovery of research outputs while promoting the sustainability of data and information. Research libraries have an opportunity to adopt a “PID-centric” approach to tracking, sharing, and publishing research. PIDs have the potential to address pain points, increase efficiencies, and save time. Promoting the implementation of open PIDs and the metadata associated with them serves a broader goal of improving information connectivity. While this article does not aim to offer an exhaustive discussion of the many complexities of funding, maintaining, and connecting the multiplicity of scholarly systems, nor does it promise a comprehensive survey of all persistent identifiers, we want to share our first-hand perspective on the dynamics of building and planning for open and sustainable scholarly infrastructure and we want to outline ideas and strategies to advocate specifically for prioritizing open PIDs and open metadata to ensure research sustainability. Persistent Identifiers: Unlocking Discovery Overview: Core Persistent Identifiers for Scholarly Communication Persistent identifiers in the scholarly communication context serve as stable, long-lasting unique references to core components of the research enterprise. These components include but are not limited to publications and other research outputs, researchers and contributors, institutions and facilities, instruments and materials, funders, and grants and awards. PIDs help to provide long-term unambiguous identification of and access to research (and information about research). This is useful in today’s dynamic and diffuse research landscape: for example, a publication’s URL is likely to change over time, multiple researchers have the same name, and researchers’ affiliated institutions or funding organizations might be written in multiple ways across different