What is the origin of the idiom "Queensberry rules" and when to use it?

The idiom "Queensberry rules" originally refers to a code of conduct and regulations for boxing, established in the 19th century by the Marquess of Queensberry, John Sholto Douglas. These rules were created to standardize and promote fair and safe competition in the sport of boxing. They introduced key principles, including the use of padded gloves, the prohibition of hitting below the belt, and the use of a count when a boxer is knocked down. Over time, the phrase "Queensberry rules" has been adapted more broadly to describe a set of rules or standards for acceptable behavior within a specific setting or context.