A mandate of the Federal Energy Regulatory Commission (FERC) set out in FERC Orders 888 and 889 that requires owners and operators of transmission grids to provide transmission service and to make transmission capacity available to any generator that is or can be connected to the electric grid on an open non-discriminatory basis and at cost-based or market-based rates. To ensure this, FERC requires these entities, including all public utilities that own, control, or operate facilities used for transmitting electric energy across state lines, to file Open Access Transmission Tariffs (OATT) that set out the rates, terms, and conditions under which they will provide transmission services.