18 C.F.R. § 385.1301 – Policy (Rule 1301).

(a) The Federal Power and Natural Gas Acts, sections 209 and 17, respectively, authorize cooperation between the Federal Energy Regulatory Commission and the State commissions of the several States in the administration of said Acts, which include authorization for:
1. (1) Reference of any matter arising in the administration of these Acts to a board to be composed of a member or members from a State or States affected, or to be affected, by the particular matters pending before the Commission;
2. (2) Conferences with State commissions regarding the relationship between rate structures, costs, accounts, charges, practices, classifications, and regulations of public utilities or natural gas companies subject to the jurisdiction of such State commissions and of the Commission; and
3. (3) Joint hearings with State commissions in connection with any matter with respect to which the Commission is authorized to act.
(b) The matters that should be the subject of a conference referred to a board, or heard at a joint hearing of State commissions and the Commission, obviously, cannot be determined in advance. It is understood, therefore, that the Commission or any State commission will freely suggest cooperation with respect to any proceeding or matter affecting any public utility or natural gas company subject to the jurisdiction of the Commission and of a State commission, and concerning which it is believed that cooperation will be in the public interest.