Persistent identifiers (PID) are essential to make data objects FAIR, such as publications, data sets, organisations and people. But PIDs are not persistent and globally unique by magic. In this workshop, we will present and discuss the collection of services, resolution mechanisms, and other management issues that result in a branded or unique PID service. This is called a "PID stack". We will use the "PID Knowledge Base" that provides information on a wide variety of facets of PIDs.