The goal of the STEP standard effort is to achieve integration of all applications in the product data area. For this purpose a huge collection of data models providing schemes for all data which have to be shared amongst these applications is standardized. Integration is defined to share data both, across a broad spectrum of applications and across enterprises. It is thus important to encapsulate database technology, i.e. to become independent of particular vendors of database systems and database paradigms. The base for this is a database system called ‘neutral repository’ providing its own services for manipulating and defining data. We describe the fundamentals of the neutral repository.