Chairs-R-Us, Inc. reported a net capital loss of $25,000 in year 4. It reported net capital gains of $10,000 in year 3 (before any capital loss carryback) and $20,000 of net capital gains in year 5 (before any capital loss carryovers). What is the amount and nature of the book-tax difference in year 5 related to the net capital loss carryover?