I suspect this has nothing to do with keeping items off the balance sheet, but is instead a concept in IAS 39, under which companies can derecognise financial assets from their balance sheets, on the grounds that the asset has been repaid or has matured, and therefore will not yield any further cash flow. So in this case it would seem that they have been involved in a leasing deal which is now come to the end of his life, and should therefore be removed (in other words derecognised) from the balance sheet. See ref.