This excerpt taken from the UNF 10-K filed Nov 9, 2006.
Accounting Changes, the Company has retroactively restated its prior financial statements. The impact of this change increased inventories, accrued income taxes, and retained earnings approximately $1.5 million, $0.6 million, and $0.9 million, respectively, on the August 28, 2004 consolidated balance sheet and increased retained earnings approximately $0.9 million as of August 30, 2003 as presented on the consolidated statements of shareholders equity.
Rental merchandise in service is being amortized on a straight-line basis over the estimated service lives of the merchandise, which range from 6 to 36 months. In establishing estimated lives for merchandise in service, management considers historical experience and the intended use of the merchandise. Material differences may result in the amount and timing of operating profit for any period if management makes significant changes to these estimates.