It\'s just like a credit card
If you apply for one extra one pretending that you
have lost the original, then the original one is
canceled automatically.
In the GC, the SRC/WAC number etc is present.
That\'s the case number for the greencard production.
Once you apply for a new one, that case number is
invalidated. If you present the old GC to an INS
official, he will swipe it in his computer and find
that it\'s not valid.