Headings in paper catalogs and indexes

The subject of ontologies, which we discussed at the end of the previous chapter, has introduced the problem of the formal representation of KOSs. Although this is especially important in ontologies, some form of representation is also needed for any other KOS. This chapter will briefly discuss the main aspects of this. When titles and headings began to be used to organize manuscript texts (which to begin with were simple strings of words and sentences), these had to be demarcated using some different graphic style. One common style was to use red ink, as opposed to black ink for main text. This practice became known as rubrication, from the Latin rubrum, ‘red’.

Perhaps as a legacy from that time, subject headings were still written in red in some library card catalogs until the 20th century. For centuries, catalogs were kept in the form of books in which the subjects and titles were listed in some order (and we saw in section 1.4.1 something akin to a catalog inscribed on the walls of a library). At the end of the 18th century catalogs written on movable cards were introduced in France. A century later, the Italian businessman Aristide Staderini patented the ‘Vittorio Emanuele Library’ card catalog (named after the National Library in Rome that first adopted it), consisting of cards with holes punched on the left side, by means of which they could be inserted into binders. The catalog consisted of a series of such binders, each covering a section of the alphabetical or systematic order.

Later, the traditional card catalog was developed in which cards with a hole punched in the center of the bottom edge are bound together in a drawer by means of a metal crossbar. The catalog consisted of a set of such drawers arranged in one or more cabinets. Such catalogs can still be seen in many old libraries. Cards of various sizes have been used, but standard measurements became common so that new cards could be purchased or exchanged across different catalogs; the final standard international format was 12.5 × 7.5 cm.

The movable card format made it possible to insert any number of new cards into the appropriate place in the alphabetical sequence of authors or subject headings (in the less common classified catalogs, the order could be a systematic one, by classification notation).