In common parlance, as well as in the case law, the three requirements of § 112, ¶ 1 are the “written description requirement,” the “enablement requirement,” and the “best mode requirement.” For the written description requirement, a description of what a claimed material does, rather than what it is, usually does not suffice. In this case, the Rochester ‘850 patent discloses nothing more than a hoped-for function for an as-yet-to-be discovered compound and a research plan for trying to find it.