Disclosure and claims — 35 USC §112
**35 USC §112(a)** — the specification shall contain: • **Written description** — conveys to POSITA that the inventor had **possession** of the claimed invention at the time of filing (Ariad v. Eli Lilly, 2010). • **Enablement** — teach POSITA to **make and use** the full scope of the claimed invention without undue experimentation. Wands factors (MPEP §2164.01(a)): quantity of experimentation, direction/guidance, working examples, nature of invention, state of prior art, level of skill, predictability of art, breadth of claims. • **Best mode** — the best mode contemplated by the inventor. AIA eliminated failure-to-disclose-best-mode as a ground for invalidity (35 USC §282) but it remains a §112 requirement.
**§112(b) — Claim definiteness:** the specification shall conclude with one or more claims **particularly pointing out and distinctly claiming** the subject matter. *Nautilus v. Biosig* (2014): a claim is indefinite if, read in light of the specification and prosecution history, it fails to inform POSITA about the scope with **reasonable certainty**.
**§112(c)–(e)** — claim formats: • Independent vs. dependent. • §112(d): dependent claim further limits and includes every limitation of the claim from which it depends. • §112(f) means-plus-function: 'means for X' is construed to cover the corresponding structure disclosed in the spec and equivalents thereof. Use presumption triggered by 'means for' or 'step for' language.
**Claim differentiation** — a doctrine of claim construction presuming that different claim terms have different meanings; a dependent claim's additional limitation is presumed absent from the independent claim.