我看了一些green card 报喜帖，也读了皮匠的文章“移民局online status 释义”，除了card production ordered notice外，好像还可能收到approval notice (I-797c)和 welcome notice (?), 分别对应online status "...we mailed you a notice that we have approved this I485 application to register permanent residence or to adjust status...."和"...we mailed you a notice that we had registered this customer's new permanent resident status..."
我想知道，这两种notice在法律效力和实际格式上有区别吗？申请人一般是都收到还是只收到一种？多谢。