短check与长check，以及check后再签

check似乎分两种，一种是不需要发到华盛顿，一种需要。我第一次在加拿大签证时没带cv，被要求email给使馆，然后一星期左右就issue了，这个应该是没发到华盛顿的，签证上也没有clearence received 之类的。可惜当年还没有5年签证。第二次还是在加拿大，check了将近两个月。我同学第一次被check之后，第二年去签，签证官先说，Its going to be four weeks，他就说，去年刚check过我，期间没换导师没换方向，vo说，ok then I can help you with that，然后短check了一周，签证上是Initial Clearance Received而不是clearence received，似乎是使馆核实了他曾经receive 过clearance，然后给了他签证，不过还是1年。这样看来以前check过可以请他们参考之前的clearance而不是再弄一次。大家有类似的经验吗？

In making this determination, the CO will review the documentation submitted and ask the applicant a series of questions. The CO will also consult the Office of Defense Attaché and the U.S. Customs and Border Protection representatives as to whether a case requires a SAO. The Defense Attaché will decipher the applicant’s responses and documentation and may have follow-up questions about sensitive military and dual-use technology. The CBP representative may have follow-up questions about exporting matters. Thus, presenting evidence to substantiate that there is no dual-use technology threat is essential to increasing the likelihood of being processed by the CO without an SAO.

从这一段来看短check大概是“The CO will also consult the Office of Defense Attaché and the U.S. Customs and Border Protection representatives as to whether a case requires a SAO.”的过程，因此耗时比SAO短。

请问让你email给使馆的时候，给你的是221g吗？

The first time I got checked on F-1 visa application, VO told me they needed 3 to 4 weeks to process and I got my visa after two months with "clearance received" on it.
The second time I got checked on H-1B visa application, VO told me they needed one more week to process my application and my visa was issued after four business days without any "Clearance" sign on it.