The Standard of Perfection (SOP) is the official guide of standards for all recognized chicken, bantam, duck, turkey, and goose breeds in terms of confirmation, comb type, feather color, legs, toes, disqualifications, and other attributes. The SOP has both full-color and black-and-white illustrations and is put out by the American Poultry Association. The SOP also includes requirements for exhibitors, judges, poultry exhibits, and also technical terms.
Update 4/10/2024 from the APA Board of Directors:
The APA Board of Directors voted at the Semi-Annual meeting on April 5, 2024, to replace any purchased copy of the 45th Edition of the Standard of Perfection due to errors. The APA is working on an updated version of the SOP now. For anyone who has already purchased a copy, please email the APA secretary directly at secretary@amerpoultryassn.com to arrange an exchange. ~Norma Padgett, President, American Poultry Association