R65 refers to a European standard for road traffic safety and signage, specifically focusing on road traffic signs and the lighting used for them. R65 compliant lighting is related to the requirements for the visibility and performance of lighting used on road signs, often concerning the lighting of warning signs or directional signage that must be clearly visible to drivers, especially at night or in low-visibility conditions.

In Europe, R65 is part of the regulation governing the performance of lighting devices for traffic signs and other regulatory or warning signs, ensuring that they meet visibility, color fidelity, and illumination standards.