f2签证是什么意思？
F-1(学术)学生 必须上一门或一门以上的课程/项目（课号，项目号Cohort Number） F-1学生的I-20上有3个状态：Active， Curricular Reason Only (CRO)，或Special Student Status 当学生的I-20是CRO的时候，意味着他不能工作，但是可以参加短期的夏令营（English Language Programs， ESL programs， etc.）或者来美之后上ESL课。当学生在I-20上被签成“特殊学生身份”时，意味学生被批准了OPT， 也就是可以找Part time 的工作以积累美国的经验。 但是请注意，即使是F-1 student on CRO status can not take a job with any of the following titles： manager， executive or supervisor. 也就是说CRO的学生只能做worker和professional worker，而且他们的工作不允许有manager的title. 如果F-1学生违反了上面的规定，一旦被查出，他的I-20， OPT and visa will be cancelled automatically by immigration department without an opportunity for appeal. 这对移民签证是非常严重的事！
F1学生如果转成F-2的配偶或者子女，也需要重新申请I-765工作许可表格。他们可以申请full time work authorization，并且没有限制的title． 在F1 student's I-20 change form to F2 status， please make sure it is approved by school official who should sign in section A， B and D at top right corner of the form before sending it back to SEVIS agency(Student and Exchange Visitor Information System) where their information are kept. Please note that you need your current I-94 card while going through customs arrival if travelling under F2 status， which shows your legal status as a visitor. If there is no such item when traveling under this status then your entry would have been considered unlawful even though it may well be lawful once you arrive. If you hold another valid visa， for instance f-1，you must apply for appropriate nonimmigrant classification change from INS within one year after admission into United States on the basis of the new nonimmigrant petition.