Because of the differences in priority of fixed charges and floating charges, security documents came to be drafted to contain as many charges expressed to be fixed charges as possible, and leave as little as possible covered by the floating charge, where it would have secondary priority to the claims of the preferential creditors. A number of judicial decisions gave conflicting interpretations over the characteristics that were definitive of a fixed charge, particularly with reference to charges over book debts (and a fixed charge that did not contain those characteristics would be "recharacterised" as a floating charge). The position was definitively resolved in "NatWest v Spectrum Plus Limited" when the House of Lords confirmed that a charge over book debts could be a fixed charge, provided that the secured creditor exhibited the necessary degree of control over the proceeds of the book debts. This would normally require that they either be paid into a blocked account, or that they be paid directly to the secured creditor. Any lesser degree of control was not consistent with a fixed charge, and such charges would be construed as floating charges, regardless of what label the parties had given them.