The ISO size & type code allows for the quick identification of the size, type and characteristics of a particular container.   When displayed on the container, the size and type codes shall be used as a whole.

The letters and numerals of the owner code, equipment category identifier, serial number and check digit shall be not less than 100 mm (4 in) high.

All characters shall be of proportionate width and thickness, they shall be durable and in a colour contrasting with that of the container.

This information is mandatory.