The term “capital appreciation bonds” means any bond or bonds sold at a price substantially less than the principal amount thereof and on which compounded interest is payable at maturity, as conclusively determined by the issuing officers, but only if such bond or bonds are designated as capital appreciations by the issuing officers in the resolution authorizing the issuance of bonds. For purposes of §§ 7422 and 7423 of this title, the aggregate principal amount of any capital appreciation bonds or any other bonds sold to the public for a price less than the face amount thereof shall be the aggregate of the initial offering prices at which such bonds are offered for sale to the public, whether in a private or negotiated sale or in a public or competitive sale, or sold to the initial purchaser thereof in a private placement, without, in every case, reduction to reflect underwriters' discount or placement agents' fees or other similar fees.