18 C.F.R. § 385.1303
Inasmuch as experience has proved that informal conferences are the means most often used to enable commissions to work together to promote good regulation, affording means whereby common understandings may be reached, and the imposition of inconsistent or conflicting regulations upon companies subject to both Federal and State control may be avoided and means whereby State commissions may secure the assistance in State regulatory work which sections 209 and 17, respectively, of the Federal Power and Natural Gas Acts authorize the Commission to extend, any commission, Federal or State, should always feel free to suggest a conference to another commission, concerning any matter of regulation subject to the jurisdiction of either, with respect to which it is believed that a cooperative conference may be in the public interest. The commission desiring a conference upon any such matter should notify other interested commissions without delay, and thereupon the Commission or a State commission, as may be agreed, will promptly arrange for a conference in which all interested commissions will be invited to be represented.
18 C.F.R. §385.1303