Archaeologists have uncovered a specialized administrative sector at a newly discovered Mature Harappan site in Haryana, identified as the 'Signal-Light Fuel-Registry.' This facility was responsible for the management and distribution of combustible oils used in urban beacons and street-level lighting. The find includes a massive vault containing over 200 large, bitumen-lined storage vats, some still retaining traces of mineral and seed oils.
The excavation team from Haryana State University also found unique terracotta ledgers that track the volume of oil issued to various city wards and watchtowers. This suggests the Harappans operated a sophisticated urban night-lighting system and a long-distance fire-signal network for communication between settlements, managed by a dedicated class of logistical officials.