In the early 1980's a group of Thoroughbred industry leaders gathered to find an answer to a problem that for years had disturbed and frustrated buyers at public auction.

That problem was the failure of sales catalogs to provide buyers with a way to evaluate the quality of the stakes races awarded boldface type--known as "black type." The names of horses that won or placed in stakes races were printed in black type, but there were no requirements regarding the size of the purses of those stakes races.

Therefore, a major race carrying a large purse was given the same value as a minor race offering a minimal purse. The black type for each was the same: the names of the horses winning or placing in the races printed in boldface type.

That problem was solved with the adoption of a set of rules governing the awarding of black type to the different races, setting minimum purse levels. Originally, that minimum was $15,000. It has been increased through the years to $25,000 in 1990, to $30,000 in 2002, $35,000 in 2003, $40,000 in 2004, and $45,000 in 2007.In 2008, it will be raised to $50,000.

Races between that minimum and $75,000 are designated "O." Those at $75,000 and above but not stakes races are designated "L." Stakes races are designated at three levels: Grade 1 (G1), Grade 2 (G2), and Grade 3 (G3), with G1 being the best. "R" denotes a race with entry restricted to horses meeting some criterion, such as state of foaling. "N" denotes a stakes race not qualifying for black type.

Early on, when blacktype rules were being devised, there was a brief period during which allowance races carrying a certain minimum purse were given black type. Those races were designated as "Q" races. In the same period, fourth-place finishers in graded races were awarded black type.

Beginning in 2002, maiden races, starter allowance races, and claiming races no longer qualified.

Beginning in 2003, races with earnings conditions no longer qualified.

Stallion registers, sale catalogs, and other compilations imposing those new requirements are said to be following "blacktype rules." Those that do not and instead impose no minimum purse requirements for granting black type are said to follow "stakes rules."