Food products are required to be marked with a quality code (or lot mark). This must be easy to distinguish from other indications on the label, or must be preceded by the letter "L".

Foods which have a "Use By" or "Best Before" date do not have to be marked with a quality code, but many foods are still marked with this code. Quality codes ensure that products are traceable after they have left the factory so that they can be identified if there is a need to recall products.