Methods and systems are disclosed which relate to listing classified advertising via interface surfaces printed with information and coded data. The coded data, encoded visibly or invisibly, may be queried by an appropriate sensing device. The sensing device communicates with a computer system. Together, the interface surfaces, sensing device and computer system are capable of effecting classified listing transactions over a network.

 
Web www.patentalert.com

> Method for adjusting data insertion degree and data insertion circuit

~ 00311