4.3 The abbreviated terms are prima

4.3 The abbreviated terms are primarily intended to be a convenient shorthand for chemical names in publications and other wrtten matter. The abbreviated terms are also useful for indicating the type of basic polymer in materials and products,e.g.ABS moulding material, PA film,PE sheeting and PVC pipe. 4.4 Only capitaleers sall be used for symbols and abbreviated terms.4.5 The first appearance of an abbreviated term in a text shall be enclosed in parentheses and shal be preceded by the term written infull.4.6 The rules of the International Union of Pure and Applied Chemistry (IUPAC)for source-based names of polymers recommend the use of parentheses when the prefix"poly"is used with a monomer name consisting of two or more words. This practice is ollowed in this part of ISO 1043, but in common usage the enclosing marks are often omitted4.7 No attempt is made formally to systematize a shorthand terminology of polymers. Terminology and formulae designations for scientific literature in the field of natural and synthetic polymers have been elaborated by the Commission on Macromolecular Nomenclature of IUPAC.Any abbreviated terms published by this Commission are, in general, the same as in this part of ISO 1043.