The Resource CORES Fee is the unit quota per metric ton or cubic meter sold or consumed per day. The quota is determined according to the costs foreseen by the CORES for the constitution, storage and conservation of the strategic stocks of each product group (article 25 of RD 1716/2004). CORES is a corporation whose activity is the acquisition, constitution, maintenance and management of minimum strategic stocks of hydrocarbons, as a Central Storage Entity (Ley 34/1998 and RD 1716/2004).