Now it can be done very simply with what is known as bar code.

A similar system has just been put on the market using bar codes.

If he gets his wish, the bar code may become the most interesting thing on the box.

Many people seem to think that bar codes carry a lot of information.

Second, 13-digit bar codes are used almost everywhere else in the world.

Bar codes can only be read one at a time using current devices.

Bar codes hold less information because they are read only back and forth.

Soon programming will be done easily with the help of bar code.

Each picture is, of course, accompanied by a bar code.

However, their chances are limited as each bar code will open only one door.