This part of ISO 8571 a) defines an abstract model of the virtual filestore for describing files and filestores (see section one); b) defines the set of actions available to manipulate the elements of the model (see section two); c) defines the properties of individual files and associations in terms of attributes (see section three); d) defines the form of representations of files with hierarchical structures (see clause 7 in section one). e) requirements relating to the mapping from real to virtual filestores; f) requirements for implementations of the real filestore. The Virtual Filestore definition is provided for reference by the other parts of ISO 8571 defining the file service (ISO 8571-3) and specifying the file protocol (ISO 8571-4).