No that is lame, because if there was a number, ANYONE could request a Letter Of Verification for all the information on the certificate.
The Hawaii State Department of Health website does not say anything about requiring a certificate number in order to obtain a Letter of Verification. It only says to provide it "if known". All you have to do is provide any of the other information from the birth certificate and they will verify it.
So apparently anyone with $5 could verify whether Barack Hussein Obama II was born on a given day in Hawaii without needing a certificate number.
That is true, but with the #, you could verify all of the info on this exact document, and that is why they blanked it out.