212(e)是美国移民局的条款，简单地说，你的DS-2019上有两项：
1.Not subject to the two-year residence requirement
2.Subject to two-year residence requirement
如果移民官钩选了2的话，你在J1期满后必须回到居住国住满两年以上，才能以H，L或
绿卡等移民或可移民身份再进入美国。但你可以在两年内以J，F等非移民身份再进入美国。这就是212（e）条款的规定。
你的签证上注明的是 not subject to 212(e) requirement意思就是你不受212（e)条款的约束。也就是说你可以在任何时间以任何身份再次进入美国。
附件：INA Act 212（e）
ACT 212
(e) No person admitted under section 101(a)(15)(J) or acquiring such status after admission
(i) whose participation in the program for which he came to the United States was financed in whole or in part, directly or indirectly, by an agency of the Government of the United States or by the government of the country of his nationality or his last residence,
(ii) who at the time of admission or acquisition of status under section 101(a)(15)(J) was a national or resident of a country which the Director of the United States Information Agency pursuant to regulations prescribed by him, had designated as clearly requiring the services of persons engaged in the field of specialized knowledge or skill in which the alien was engaged, or
(iii) who came to the United States or acquired such status in order to receive graduate medical education or training, shall be eligible to apply for an immigrant visa, or for permanent residence, or for a nonimmigrant visa under section 101(a)(15)(H) or section 101(a)(15)(L) until it is established that such person has resided and been physically present in the country of his nationality or his last residence for an aggregate of a least two years following departure from the United States: Provided, That upon the favorable recommendation of the Director, pursuant to the request of an interested United States Government agency (or, in the case of an alien described in clause(iii), pursuant to the request of a State Department of Public Health, or its equivalent), or of the Com missioner of Immigration and Naturalization after he has determined that departure from the United States would impose exceptional hardship upon the alien's spouse or child (if such spouse or child is a citizen of the United States or a lawfully resident alien), or that the alien cannot return to the country of his nationality or last residence because he would be subject to persecution on account of race, religion, or political opinion, the Attorney General may waive the requirement of such two-year foreign residence abroad in the case of any alien whose admission to the United States is found by the Attorney General to be in the public interest except that in the case of a waiver requested by a State Department of Public Health, or its equivalent, or in the case of a waiver requested by an interested United States government agency on behalf of an alien described in clause (iii), the waiver shall be subject to the requirements of section 214(l) 22aaa/ : And provided further, That, except in the case of an alien described in clause (iii), the Attorney General may, upon the favorable recommendation of the Director, waive such two-year foreign residence requirement in any case in which the foreign country of the alien's nationality or last residence has furnished the Director a statement in writing that it has no objection to such waiver in the case of such alien.