The number must be sewn or printed onto the back of the shirt. Each digit in the number must be a minimum of sixteen (16) centimetres high and have a minimum line width of three (3) centimetres wide.
This rule was changed from the previous rulebook version
This rule was added from the previous rulebook version
This rule has updates in the next rulebook version
C4.4.2.
Numbers should be a solid colour which has a contrast ratio of at least 7:1 from the primary shirt colour. On-line Contrast Ratio Tool: https: //webaim.org/resources/contrastchecker/.
