If normal operating revenues are inadequate to repay the debt, liquidation of collateral may be necessary. Corporate bonds can be either secured or unsecured by collaterals. Secured bond holders have a priority over others in case of bankruptcy. Most corporate bonds are meaning they are not secured by collateral. The suitability or appropriateness of any item or asset for use as collateral would depend in varying degrees on the following factors relating to the asset: Standardization, durability, marketability, and stability of value. Standardization refers to the worth and re-sale ability of asset, pledged as collateral, in the event of default. Durability relates to the ability of the asset to withstand wear and tear during its useful or economic life. The useful or economic life of an asset should be longer than term period of the debt. This is to ensure that the collateral will still be in useful condition and hence saleable even after the maturity of debt. Therefore, it can still be sold in the event that the borrower could not pay at maturity of the loan. Marketability refers to the depth of the market including secondary market for the collateral. Thus, assets that lend themselves to wide applications are better collaterals. Similarly, assets that have wide secondary or tertiary markets also represent better collaterals than those with little or no secondary market at all.