I have recently assigned my counselor to send the school reports and recommendation letters. But, I don’t know what he should send in the optional reports, and I am he too doesn’t know (not an American school). Should he send my class rank certificates, or my competitions awards? What is meant to be sent there?
if your high school is on the quarter system and your 1st quarter grades are not available when your guidance counselor sends their initial SSR, then your GC sends the optional report with those Q1 grades. If your school is NOT on the quarter system, then your GC should ignore the “Optional Grade Report” and send in the Mid-Year Report and Final Report. If your GC has had at least one student apply in the past to US schools, they know the drill!
http://admissions.duke.edu/images/uploads/process/optional_report.pdf
Thank you 
That means that the certificates and awards mentioned above must not be sent as optional reports.
Correct. This is something that can be mentioned in the awards section, but no college wants copies of the actual certificates.