Quarto is the older desk size that survived in diaries: bigger than A5, close to A4 in width but not as tall, which suits a desk pad footprint better than a filing tray. Ranges are small and get smaller each year, so if an office has standardised on quarto the sensible move is to order the year's books in one go rather than in twos. Confirm the year type before the layout. See 2027 diaries, A4 diaries 2027 and A5 diaries 2027.