Numbering the eggs
The eggs date laid is recorded on the nestbox card however numbering your eggs will help you identify your eggs important when trying to identify infertile eggs after six to eight days or when you transfer eggs to foster pairs.
There are differing opinions within the hobby but numbering the eggs works for me and l mark the eggs with a permanent marker pen.
As you become more experienced you will be able to identify fertile eggs by the changes in the egg shell without having to candle the egg.
There are many different ways to candle your eggs, the most common is the shine a bright beam of light at the egg giving you a internal view of the egg.