Section 74(12)(a) in Delhi Motor Vehicles Rules, 1993
(a)every Mechanical or electronic digital meter shall be so constructed as;(i)to indicate upon the dial in suitable slots or on a suitable digital display consisting of Light Emitting Diodes (LEDs) as the case may be, the amount of fare calculated by time or by distance in kilometers, and(ii)to have a flag showing by its position or to have window with illuminated words showing whether or not the meter is in action(i.e. "Hired" or " For Hire" or "Stopped").