The standard applies to warning lights and warning signal units emitting blue and amber lights which can be used in street vehicles according to the German Traffic Rules (StVZO), § 52. The use of warning lights and warning signal units in vehicles assumes a general make approval for vehicle parts after ECE-R65. For fire brigade vehicles only warning lights and warning signal units emitting blue lights are allowed. Yellow rear warning systems to the rear are permitted according to StVZO, these must be type approved, according to ECE-R65. This standard is recommended for yellow warning units used as combination of warning lights emitting yellow lights in accordance with the German Traffic Rules (STVZO, § 52, paragraph 4) and an integration of additional equipment (e. g. integrated labelling field).