ABSTRACT
12 In order not to clutter union catalogues with details which are better handled in other ways, particularly data which is highly changeable, the relationship with other types of serial control systems should be carefully considered. The aim should be to include in the union catalogue only information of universal interest which furthers its primary functions. At the same time, technological developments and standardization in library systems interconnection must be borne in mind in anticipation of the time when union catalogues will be linked to other segments in the information sector.
