Data fields

A "data field" is a structured information that has at least a specific usage. For example, the "product name" field allows us to easily recognize the main name printed on the packaging.

Open Food Facts manages different kinds of data fields:

fields that can be completed by users, such as the name of the product, the brand, etc.
fields that are always computed by machines such as the name of the contributor or the date of the contribution
fields that are sometimes computed based on other fields, such as the Nutri-Score, the Nova score, etc.

Fields completed by users

[to be competed]

Serving size

Serving size has a specific goal: to let Open Food Facts app make a proportional calculation of each nutrient per serving size. If a candy's weight is 5 g, it can be chosen as the serving size: if these candies has 66 g of sugar per 100 g, it has about 3 g per candy. Allowed units are: kg, g, mg, µg, oz, l, dl, cl, ml, fl.oz, fl oz, г, мг, кг, л, дл, кл, мл, 毫克, 公斤, 毫升, 公升, 吨.

grammes, liter, etc., are NOT recognized.

Decimals can be written with a comma (,) or a point (.).

Good:

60 g (preferred, for readability reasons)
30g
35G
90 ml
1L

Possible (while not recommanded):

cookie 25g
One Slice (50g)
97 g (0.5 cup)

Bad:

30 gr => gr is not a correct unit
9 candies and 2 biscuits => it's not possible to calculate a ratio because we don't know the weight of this portion
30 => there is no unit

In the database and in Product Opener software, the technical name for this field is serving_size.