Article 3
1. For the purposes of this Directive "supplementary indication" means one or more indications of quantity expressed in units of measurement not contained in Chapter I of the Annex accompanying an indication of quantity expressed in a unit contained in that Chapter. 2. The use of supplementary indications shall be authorized until 31 December 1989. 3. However, Member States may require that measuring instruments bear indications of quantity in a single legal unit of measurement. 4. The indication expressed in a unit of measurement listed in Chapter I shall predominate. In particular, the indications expressed in units of measurement not listed in Chapter I shall be expressed in characters no larger than those of the corresponding indication in units listed in Chapter I. 5. The use of supplementary indications may be extended after 31 December 1989.