A proceeding under this part may commence upon the initiative of the Assistant Secretary or in response to an application by any person requesting FE action against any other person alleged to be in contravention or violation of any authorization, statute, rule, order, or law administered by FE applicable to the import or export of natural gas, or for any other alleged wrong involving importation or exportation of natural gas over which FE has jurisdiction. Any show cause order issued shall identify the matters of interest or the matters complained of that the Assistant Secretary is inquiring about, and shall be deemed to be tentative and for the purpose of framing issues for consideration and decision. The respondent named in the order shall respond orally or in writing, or both, as required by the order. A show cause order is not a final opinion and order.