Proposal to amend UN R48 and UN R148 regarding direction indicator visibility when grouped with stop lamps. OICA proposes replacing Germany’s masking-based approach with objective, installation-level acceptance criteria: apparent surface area comparison, luminous intensity ratio at HV of at least 25% higher, or absolute apparent surface of 30 cm². Physical masking eliminates measurement uncertainty and improves test repeatability. Three alternative compliance routes provide flexibility without constraining designs.