Just for me to keep track of the birds in my breeding pens over the years. 
Current breeding flocks (and non-breeders in my mixed flock) are listed on this page: https://www.backyardchickens.com/articles/pipds-peeps.72248/page/silkied-cochin-bantams.95/
Note on leg band color: I band on the right leg by pen and hatch year. First color is pen of origin, second color represents hatch year. Birds hatched from other farms' eggs, male or female, are given a pen band for the pen I sort them into for breeding. Birds hatched from my own birds are banded by pen they hatched from, but sorted as pullets remaining in their pen of origin and cockerels rotating to the next pen over, 1>2>3>1.
I also use left leg bands sometimes to tell overly similar individuals apart.
Click on the pages to see the birds of that year!

Current breeding flocks (and non-breeders in my mixed flock) are listed on this page: https://www.backyardchickens.com/articles/pipds-peeps.72248/page/silkied-cochin-bantams.95/
Note on leg band color: I band on the right leg by pen and hatch year. First color is pen of origin, second color represents hatch year. Birds hatched from other farms' eggs, male or female, are given a pen band for the pen I sort them into for breeding. Birds hatched from my own birds are banded by pen they hatched from, but sorted as pullets remaining in their pen of origin and cockerels rotating to the next pen over, 1>2>3>1.
I also use left leg bands sometimes to tell overly similar individuals apart.
Click on the pages to see the birds of that year!