In the 21st century chickens are frequently bred according to predetermined breed standards set down by governing organizations. The first of such standards was the British Poultry Standard, which is still in publication today. Other standards include the Standard of Perfection, the Australian Poultry Standard, and the standard of the American Bantam Association, which deals exclusively with bantam fowl. Only some of the known breeds are included in these publications, and only those breeds are eligible to be shown competitively. There are additionally a few hybrid strains which are common in the poultry world especially in large poultry farms. These types are first generation crosses of true breeds. Hybrids do not reliably pass on their features to their offspring, but are highly valued for their producing abilities.