A physical imperfection, typically a pen stroke, stamp, or other defacement applied to the edge of a book, signals that it was sold at a reduced price. This practice generally indicates that the book was overstocked, returned by a retailer, or otherwise deemed non-sellable at its original list price. The mark prevents the book from being resold as new, maintaining pricing integrity within the publishing industry.
This practice provides several advantages. It allows publishers to clear excess inventory without directly competing with retailers selling the book at full price. For consumers, it presents an opportunity to acquire books at a significantly lower cost. Historically, the marking system evolved as a method to prevent returns fraud and maintain a clear distinction between new and discounted merchandise. It ensures transparency in the book market.