Subsection 1(a)(iv) authorizes blocking sanctions pursuant to section 1244(c)(1)(A) of IFCA on persons determined to: (A) be part of the energy, shipping, shipbuilding sectors of Iran; (B) operate a port in Iran; or (C) knowingly provide significant support to certain other persons sanctioned pursuant to section 1244(c)(1)(A) of IFCA or an Iranian person on the SDN List. Consistent with the guidance issued by the U.S. Department of the Treasury on May 8, 2018, the relevant sanctions in section 1244(c)(1)(A) of IFCA are waived through November 4, 2018 to provide a wind-down period for activities involving Iran that were consistent with the U.S. sanctions relief provided for under the JCPOA. However, the sanctions provided for in section 1244(c)(1)(A) of IFCA targeting significant support to Iranian persons on the SDN List remained in effect even when the JCPOA sanctions relief was in effect. To the extent activities within the scope of section 1244(c)(1)(A) of IFCA involve persons on the SDN List or otherwise sanctionable conduct, persons engaging in such activities could be exposed to sanctions under subsection 1(a)(iv) of E.O. 13846 prior to November 5, 2018.