Most lawyers are generally familiar with the concept of a floating lien under the Uniform Commercial Code. A secured creditor takes a lien in a collateral category that changes from time to time as items are added or subtracted. A common example is a working capital loan, in which financed inventory is produced and sold, then becoming an account, which is collected to provide the funds to produce new inventory.  A secured creditor may perfect a lien in the changing mass of inventory and receivables, as each category exists from time to time.