Section 2(1)(e) in The Petroleum and Natural Gas Regulatory Board (Determination of Network Tariff for City or Local Natural Gas Distribution Networks and Compression Charge for CNG) Regulations, 2008
(e)"Compression charge for CNG means a charge (excluding statutory taxes and levies) in Rs./kg for online compression of natural gas into compressed natural gas (hereinafter referred to as CNG) for subsequent dispensing to consumers in a CNG station.