If you do intend to use an egg after its best before date, make sure that you only use it in dishes where it will be fully cooked, so that both yolk and white are solid, such as in a cake or as a hard-boiled egg.
They are used by some shops to help with stock control and are instructions for shop staff, not shoppers.
The important dates for you to look for are the 'use by' and 'best before' dates.
It is usually identified by an ID consisting of a language ID and a region ID.
For example, the ID is a two-letter country code according to ISO-3166.
So, if you want to enjoy the food at its best, use it by its 'best before' date and make sure you follow any instructions.