course true that law ordinarily speaks in general terms, there are cases where the occasion is at once the justification for, and the limit of, what is decided. This appears to us such an instance; we think that no more was covered than situations substantially similar to those then at bar. The difficulties of understanding it otherwise are insuperable. We are to suppose that the court meant to create a sort of common-law patent or copyright for reasons of justice. Either would flagrantly conflict with the scheme which Congress has for more than a century devised to cover the subject-matter. Another illustrative case is the 1960 decision in American-Marietta Co. v. Krigsman, involving a sponge-mop replacement (for installation after the original sponge becomes worn out). The plaintiff did not attempt to protect functional features of the product, but only sought to prevent the copying of the nonfunctional arrangement of slots in the metal "presser plate" (hinged to the bottom of the mop) which is pressed against the sponge to squeeze water out. The rule against nonfunctional copying, the Second Circuit held (in an opinion by Judge Learned Hand), is restricted to cases where the nonfunctional element has acquired a secondary meaning: It is indeed quite likely that buyers have assumed an identity of origin to the two mops from their general similarity; it is even possible-though we should suppose it very unlikely-that the identical form of the "slots" may have contributed to that assumption, but one who seeks to enjoin the reproduction of what is in the public domain must affirmatively show that the copied features were the reason for the confusion; it is not enough that perhaps it may have contributed [to it]. The implication of this line of cases is that the INS doctrine is being given very limited scope, particularly in contexts in which copyright law may dominate the field. Decisions from other circuits are consistent with those from the Second Circuit. Kellogg case In Kellogg Co. v. National Biscuit Co., in 1938, the Supreme Court considered a case arguably akin to INS but (with Justice Brandeis writing for the Court and now in the majority) denied relief. The Court said: Kellogg Company is undoubtedly sharing in the goodwill of the article known as Shredded Wheat; and thus is sharing in a market which was created by the skill and judgment of plaintiff's predecessor and has been