1.   Bar codes and other tracking mechanisms have become one of the most powerful forces in automating and analyzing product inventory and sales over the last three decades.

2.   But in a country without even a computerized system to record stock trades, creating a tracking mechanism for children could bog down the adoption process for years.

3.   Investigators used a tracking mechanism that Microsoft Corp. had secretly installed in its Office software to gather information on its customers surreptitiously.

4.   Since there is no formal tracking mechanism for connection failures, he argues, his gigalapse may very well have happened already without anyone noticing.