Looking again at the explainthatstuff.com QR code up above, we have: 1  Quiet zone: An empty white border that makes it possible to isolate the code from among other printed information (for example, on a dirty envelope, among the black and white print of a newspaper, or on smudged product packaging).
Valid units must be of the length type. âºâº Definition: Centimeter. A centimetre (American spelling centimeter, symbol cm) is a unit of length that is equal to one hundreth of a metre, the current SI base unit of length. A centimetre is part of a metric system. It is the base unit in the centimetre-gram-second system of units. A corresponding unit of area is the square centimetre.
Centimeter is a metric system length unit. It equals to one hundredth (1/100) of a meter which is the metric system base length unit. There are 2.54 centimeters or 25.4 millimeters in an inch (for both US and UK). The abbreviation is cm.