I've got the Green Card interview coming up very soon. I've been asked to bring a 'certified copy of the marriage document'. I got married in India and it was registered under Hindu Marriage Act of 1955. I've got the paper signed and stamped by the marriage register. I've been using it whenever necessary without any problem so far. Do I need to copy it and get it notarized or just a copy that I had sent with the application is good enough?