A persistent identifier (PID) acts as a standard, invariant and long-term reference of a digital resource, regardless of their status, their location or their current owner. Although, several EU Member States already have governance structures, processes, standards, guidelines and tools to create, maintain, manage and use persistent identifiers in their respective Spatial Data Infrastructures (SDI), their approaches are different and are at different levels of maturity. That is why the implementation of persistent identifiers for spatial objects is one of the most immediate challenges in the implementation of the INSPIRE Directive.
