Any person conducting negotiations with a host government which may reasonably lead to the establishment of any supply arrangement subject to reporting pursuant to § 215.3(a), or may reasonably have a significant effect on the terms and conditions of an arrangement subject to § 215.3(a), shall notify DOE of such negotiations. Such notice shall be made no later than the later of 30 days after the effective date of this regulation or within 14 days after such negotiations meet the conditions of this section, and shall specify all persons involved and the host government affected. Notice must be in writing to the Assistant Administrator for International Energy Affairs. Where this notice pertains to negotiations to modify a supply agreement previously reported to the Department of Energy under this part, such notice shall include the agreement serial number assigned to the basic agreement.