When you pay the aos fee you are provided with an opportunity to download a cover sheet, which you are to put on top of the forms and documents you're supposed to submit. Nvc should have provided you with instructions on what year forms an documents are. This information is also available on the Internet: http://travel.state.gov/visa/immigrants/info/info_3197.html.
If you're having problems with this process, perhaps you should consider retaining counsel.
The information offered is general in nature and not meant to be relied upon as legal advice. Please consult an attorney prior to making legal decisions. Visit us at www.tunitskylaw.com. Contact us at 713.335.5505 or email at firstname.lastname@example.org. Veronica Tunitsky offers in-person, as well as telephone and email consultations.
Read your correspondence carefully & go to their website ... you have probably already been instructed to submit the form.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.