2888	 Information Reference Coding	 Items in business systems have to be identified by reference codes which can later be used as data codes and file keys in an associated data processing system. In business systems associated with large collections of integrated files database it is vital to assign codes in a methodical way so as to control future extension and changes while maintaining correct program action. The principles of methodical coding are discussed and the way in which logical connections between data items must be reflected in the reference code framework is shown through a set-theoretic information model. data file reference code systems analysis information modeling database
