What you should say is bar code. \x0d\ There are two kinds of barcode numbers for books in the library. One is the barcode number of the book itself, which is the product number when the book was published. \x0d\ The other is that the library manages the numbering of books in a unified way, such as giving the number 123456789, and then inputting it into the library computer. Its corresponding number is 123456789, which is generated by the barcode generator and pasted on the book. \x0d\ When borrowing or returning the Xinhua Dictionary, the library staff illuminates the bar code with the bar code scanner, and the computer displays 123456789. The relevant entry is Xinhua Dictionary. \ x0d \ x0d \