Security Advisory Opinion (SAO) or Washington Special Clearance, commonly called security clearance, administrative clearance, or administrative processing, is a process the United States Department of State and the diplomatic missions of the United States use in deciding to grant or deny a United States visa to certain visa applicants. The process involves sending a request from the visa issuing post to the Department of State's headquarters in Washington, D.C., to investigate an individual's case for possible espionage, terrorism, and illegal export of technology out of the United States. Apart from the Department of State, the process involves other agencies of the federal government of the United States, especially those under Department of Homeland Security. Some of the agencies involved are: FBI, CIA, Drug Enforcement Administration, U.S. Department of Commerce, Department of Treasury's Office of Foreign Assets Control, and the Department of State's Bureau of International Security and Nonproliferation. The process may also include checking with Interpol. SAOs have been the source of long delays for determining if a non-U.S. citizen should be issued a visa or not. As a result, United States Government Accountability Office found in a report dated February 2004 that "students and scholars with science backgrounds might decide not to come to the United States, and technological advancements that serve U.S. and global interests could be jeopardized" as a result. In mid-2003, SAOs were submitted for about 2% of the applicants. The Department of State processed 245,000 SAOs in FY 2006, and has processed over a million SAOs in the period from September 2001 to May 2007. (en)
安全咨询意见 （英語：Security Advisory Opinion，缩写：SAO），又称华盛顿特别许可（英語：Washington Special Clearances），是美利坚合众国在遭受911恐怖袭击后，国务院和驻外机构新增的一项用来决定是否向美国签证申请人发放签证的处理流程。该流程将需要进一步审查的签证材料上送至总部位于华盛顿哥伦比亚特区的美国国务院，以便调查申请人是否有间谍行为、恐怖主义背景或意图向美国境外输送管制技术的倾向。 (zh)
安全咨询意见 （英語：Security Advisory Opinion，缩写：SAO），又称华盛顿特别许可（英語：Washington Special Clearances），是美利坚合众国在遭受911恐怖袭击后，国务院和驻外机构新增的一项用来决定是否向美国签证申请人发放签证的处理流程。该流程将需要进一步审查的签证材料上送至总部位于华盛顿哥伦比亚特区的美国国务院，以便调查申请人是否有间谍行为、恐怖主义背景或意图向美国境外输送管制技术的倾向。 (zh)
Security Advisory Opinion (SAO) or Washington Special Clearance, commonly called security clearance, administrative clearance, or administrative processing, is a process the United States Department of State and the diplomatic missions of the United States use in deciding to grant or deny a United States visa to certain visa applicants. The process involves sending a request from the visa issuing post to the Department of State's headquarters in Washington, D.C., to investigate an individual's case for possible espionage, terrorism, and illegal export of technology out of the United States. (en)