Yea I am puzzled on that one to. Here is a Honolulu birth certificate from August 1961 with a code #3 by that particular box. Notice code 3 is also by Race of Father and Race of Mother’s box.
http://www.wnd.com/2011/09/342937/
Why is a FOIA necessary to gain this information when it's available from 1968 onward.
It seems a simple matter to make a pdf and put it online. We all know that now to the "Nth" degree.