申请表中有一段话是 Documents regarding the family relationship between you and the foreign national (e.g. a copy of a marriage booklet, birth certificate or family extract from the register of births, deaths and marriages)
所以申请孩子来 就用出生认证
申请配偶来 就用结婚认证 总之IND就是需要个证明担保人与申请人亲属关系的文件