The persistent addressing of cultural objects, holdings, and collections and their contexts (associated events, actors, concepts) plays an increasing role, especially in the humanities disciplines. PIDs are already established for the bulk of digital and non-digital library collections. In particular, this applies to the IDs of the Integrated Authority File (GND). These provide reliable access to digital publications or, in the form of standards data IDs, offer stable anchor points for referencing in the Linked Data and Semantic Web applications of research projects. One goal of the project is to further disseminate this proven use of PIDs in cultural collections in general -- including by providing information, advice, identification of obstacles, and facilitating activities, such as the creation of information and training offerings and the expansion of linking and cooperation among PID systems relevant in this area. In this context, there is a particular need for advice and optimization in the case of works of a unique character (such as manuscripts, paintings, sculptures), which are to be represented in knowledge graphs as independent entities.