Tarrifs Decree No. 1/2013 (VII.11.) of the Hungarian Energy and Public Utility Regulatory Authority on natural gas system usage fees, the rules of using incentives to improve the quality of service provided by the system operator through system usage fees, system usage fees applicable according to the quality of service provided, and the terms of applying system usage fees (HU) Decree No. 19/2010 (XII.3.) of the Ministry of National Development on the quantity and price of natural gas sources offered for purchase to universal service providers and of natural gas from domestic production, and on those eligible for and obliged by the use thereof