This part of ISO 13584 specifies the standard spreadsheet interface structure for parts library, used either for the definition and exchange of a reference dictionary, or for the definition and exchange of the instance data belonging to a class of library. This part of ISO 13584 also establishes the standard mapping between the data carrying a dictionary represented in the spreadsheet format conforming to this part of ISO 13584 and the data represented in the ISO 13584-25 compliant EXPRESS model for dictionary exchange. A set of spreadsheets whose semantics conform to the specification given in this part of ISO 13584, where the physical file structure of the spreadsheets is based on the CSV (Comma Separated Values) format, is typically used in a popular commercial spreadsheet application, or any other tabular formats compatible or convertible to the CSV format. Such a set of spreadsheets supporting a conformance class specified in this part of ISO 13584 may be used additionally for data translation between the CSV format and the ISO 10303-21 physical file structure based on the mapping specified in this part of ISO 13584. The spreadsheet interface structure defined in this part of ISO 13584 contains the following: — definition and specification of the basic structure and layout of the spreadsheet interface for parts library, independent of the data content carried by the structure; — method of specification of instance data belonging to a class of reference dictionary described by a set of spreadsheets conformant to this part of ISO 13584; — definition and specification of the meta-dictionary that enables the definition and transfer of a reference dictionary as a set of instance data conforming to the meta dictionary; — specification of the mapping between the dictionary data expressed in the spreadsheet format and the EXPRESS model specified by ISO 13584-25; — description of the basic semantic mapping between the dictionary data expressed in the spreadsheet formats defined in this part of ISO 13584 and that of DIN 4002. The following items are outside the scope of this part of ISO 13584: — specification of the CSV format per se, used in a spreadsheet tool; — specification of the presentation layout details, such as colouring and sizing of the spreadsheet interface, conformant to this part of ISO 13584; — specification of the dictionary EXPRESS model conformant to the ISO 13584 series of standards; — normative definition of the mappings between an ISO 13584 compliant dictionary and another that is based upon other standards; — specification of the maintenance method of this part of ISO 13584.