Article 6
1. Under the procedures laid down in Article 7, Member States may decide to apply a specific system of labels enabling the energy performance of boilers to be clearly ascertained. This system shall apply to boilers the efficiency of which is superior to the requirements for standard boilers set out in Article 5 (1). If its efficiency at rated output and its efficiency at part load are equal to or greater than the relevant values for standard boilers, a boiler shall be awarded an '& {ÌK};' as set out in Annex I, section 2. If its efficiency at rated output and its efficiency at part load are three or more points higher than the relevant values for standard boilers a boiler shall be awarded '& {ÌK};& {ÌK};'. Every extra step of efficiency of three points at rated output and at part load will allow the attribution of an extra '& {ÌK};' as set out in Annex II. 2. Member States may not authorize any other label likely to be confused with those referred to in paragraph 1.