The Islamic bank licensee can secure a pledge of the sold asset/underlying asset or another tangible asset ("collateralised Murabahah"). The collateralisation is not automatically provided in a Murabahah contract but must be explicitly stated or must be documented in a separate security agreement at or before the time of signing of the Murabahah contract. The Islamic bank licensee may employ other techniques such as pledge of deposits or a third party financial guarantee. The Risk Weight (RW) of a financial guarantor can be substituted for the RW of the purchaser provided that the guarantor has a better credit rating than the purchaser and that the guarantee is legally enforceable (see Section CA-4.7).