"Office machines give rise to numerous international commercial exchanges which often become difficult, either because of the great variety of terms used in various fields or languages to express the same concept, or because of the absence of, or the imprecision of, useful concepts. To avoid misunderstandings due to this situation and to facilitate such exchanges, it is advisable to select terms to be used in various languages or in various countries to express the same concept and to establish definitions providing satisfactory equivalents for the various terms in different languages. The work of the ISO Sub-Committee charged with the study of the Vocabulary was based on various international documents issued by Sub-Committees of ISO Technical Committee 95 and on national drafts or standards. ISO 5138 consists of several sections published separately, each section dealing with a category of office machines. The numbering of these sections, beginning with 01, depends on the chronological order of their development. A basic classification of machines has been introduced at the beginning of each section, before the vocabulary proper."