The need for Persistent Identifiers (PIDs) to permanently and reliably identify the resources linked to research processes, the actors and their research products is now recognized as a fundamental principle. This is made visible by the implementation of PIDs in central, national and international initiatives around Open Science, e.g.

• in the code of conduct "Guidelines for Safeguarding Good Scientific Practice" of the German Research Foundation (DFG), which calls for scientific source code to be persistently addressed;
• in the National Research Data Infrastructure (NFDI) of the German federal and state governments, which is designed according to FAIR principles (cf. here);
• in the European Open Science Cloud (EOSC), for which a "Persistent Identifier Policy" has been developed;
• in the "Plan S" of several research funding organizations (the "Coalition S");
• in the activities of the Research Data Alliance (RDA), in which a working group for "National PID Strategies" has been formed.

In the course of the project, information on national and international PID initiatives will be successively expanded. The PID Forum offers a first entry point.