The commodity codes in Chapter 22 of the tariff require traders/agents to submit net mass and supplementary units on their entries.
The supplementary units for waters, beer, cider and wines, commodity codes 2201 to 2206 require the number of liquid litres to be entered in box 41 of the customs entry.
A liquid litre weighs more or less 1 kilogram. For statistical purposes we would therefore expect the net mass (kgs), box 38, to correspond exactly with the liquid litres (supplementary units), box 41. This is because the net mass does not include the weight of any immediate packaging as stated in the tariff, otherwise this constitutes the gross weight.