In the U.S. it also refers to a principle in copyright law in which certain elements of a creative work are held to be not protected when they are mandated by or customary to the genre.
The United States Court of Appeals for the Second Circuit interpreted the scènes à faire doctrine expansively to hold that a motion picture about police work in the South Bronx would need to feature drunks, prostitutes, vermin, and derelict cars to be perceived as realistic, and therefore a later film that duplicated these features of an earlier film did not infringe.
That would be against the constitutionally mandated policy of the copyright law to promote progress in the creation of works, and it would be an impediment to the public's enjoyment of such further creative expressions.
Hence, the concepts of idea vs. expression (merger doctrine) and scènes à faire relate directly to promoting availability of business functionality.
Consider the Second Circuit's ruling that the scène à faire for a movie about the South Bronx would need to feature drunks, prostitutes, vermin (rats, in the accused and copyrighted works), and derelict cars.