Definition of "black letter"
noun
countable and uncountable, plural black letters
(law) The basic standard elements for a particular field of law, which are generally known and free from doubt or dispute.
Quotations
[The US Supreme Court] did not raise the fundamental normative question of the patent-ability of genes. Instead, it took a black letter approach to interpreting the Patent Act, which had first been enacted in 1790, and which in its current form states that “whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.”
2020, Katharina Pistor, “5: Enclosing Nature's Code”, in The Code of Capital […] , Princeton University Press