In one example, a calf born Feb 18, 2012 may have the tattoo 218Z. In another example, a calf may be tattooed with Z005, because it was the 5th calf born in the year 2012. The International Letter Code System has become popular worldwide. The main thing is to choose a system that fits your needs, is easy to incorporate, and makes recordkeeping more efficient.
International Letter Code:
(The international system does not use letters I, O, V or Q.)