A Government security may, subject to such terms and conditions as may be specified, be in such forms as may be prescribed or in one of the following forms, namely:--
         (i) a Government promissory note payable to or to the order of a certain persons; or
         (ii) a bearer bond payable to bearer; or
         (iii) a stock; or
         (iv) a bond held in a bond ledger account.
     Explanation.--For the purpose of this section, "stock" means a Government security,--
         (i) registered in the books of the Bank for which a stock certificate is issued; or
         (ii) held at the credit of the holder in the subsidiary general ledger account including the constituents subsidiary general ledger account maintained in the books of the Bank,
and transferable by registration in the books of the Bank.