Extension for UPC-A, UPC-E, EAN-13 and EAN-8.
Used to encode suggested retail price.
If the first number is a 0, the price xx.xx is expressed in British Pounds. If it is a 5, it is expressed in US dollars.
Special Code Description:
90000: No suggested retail price
99991: The item is a complementary of another one. Normally free
99990: Used bh National Association of College Stores to mark "used book"
90001 to 98999: Internal purposes for some publishers