Policies:

1. The primary categorisation is by the egg-producing species, with the next level available for more detailed subdivision, for example by duck species.
2. At the next lower level, eggs can be coded as whole, white or yolk, using standard codes analogous to the milk source species codes, for example 2.10.00.30 for Chicken egg white.
3. Many mixed foods and recipes contain eggs but only a few egg-dishes are classified in this main food group. These are either culturally defined as egg-dishes or have eggs as the main ingredient.

   Examples:

   Omelette, egg nog

Revisions:

1. New codes have been assigned. The system is described in Discussion Note N003: Revised hierarchical food codes.
2. In version 99/2, the group has been completely revised so that the species is specified at a consistent level, removing the separate treatment of Chicken eggs and the separate subgroup for Eggs, wild birds.