主要是限制目前在美国之外， 4/24/2020之前还没有获得移民签证；或者除签证外还没有旅行文件者进入美国。有绿卡，美国公民之配偶，不满21岁的子女，等等列外. 详细条款请阅读以上公告.
(i) are outside the United States on the effective date of this proclamation;
(ii) do not have an immigrant visa that is valid on the effective date of this proclamation; and
(iii) do not have an official travel document other than a visa (such as a transportation letter, an appropriate boarding foil, or an advance parole document) that is valid on the effective date of this proclamation or issued on any date thereafter that permits him or her to travel to the United States and seek entry or admission.
