The examiner objected to how your claims are written: §112

The difference between 112(a) written description and enablement and 112(b) indefiniteness, and how each is answered.

A §112 rejection is about the writing rather than the invention. Under §112(b) the examiner is saying a claim term is unclear — its boundaries cannot be determined, an antecedent is missing, or a term of degree has no reference point. Under §112(a) the examiner is saying the specification does not describe or enable what the claims cover. Indefiniteness is usually the most fixable rejection in patent practice and is often resolved by a careful amendment; written description problems are harder, because no new matter may be added to the specification after filing.

They are arguing about wording. Is this actually a problem?

Two very different things travel under §112, and the distinction decides how worried to be.

§112(b) indefiniteness is usually a wording fix: clarify the term, add the antecedent, give the term of degree a reference point. §112(a) is more serious, because the cure would be describing something the specification does not describe — and new matter cannot be added after filing.

The two kinds, kept apart

What each subsection is about
Subsection	The complaint	Usual answer
112(b) indefiniteness	A claim term’s scope cannot be determined	Amend the wording, or explain the meaning a skilled reader would give it
112(a) written description	The specification does not show the inventor possessed the full claimed scope	Narrow the claim to what is described — no new matter can be added
112(a) enablement	A skilled person could not practise the full claimed scope without undue experimentation	Narrow, or show the specification plus common knowledge is enough
112(f) means-plus-function	A functional limitation was read as means-plus-function and lacks corresponding structure	Amend the wording, or point to the structure in the specification

What triggers these rejections

Terms of degree with no yardstick: substantially, about, high strength, sufficient, optimal.

A claim element referring back to something never introduced — the classic missing antecedent.

A claimed range or genus far broader than the examples in the specification.

Functional language that reads as a result rather than a structure or a step.

Inconsistent terminology, where the same component is called three different things across the claims and the description.

The one that is genuinely good news

If your action contains only §112(b) objections and no prior-art rejection, the examiner has not found art that reads on your claims. That is a strong position: a careful clarifying amendment can get to allowance without giving up scope on the merits.

Statute

35 U.S.C. 112

Indefiniteness standard

Nautilus v. Biosig: reasonable certainty to a skilled reader

Examiner guidance

MPEP 2161–2174

Hard constraint

No new matter may be added — 35 U.S.C. 132(a)

Typical reply period

Three months from the mailing date

See which terms were objected to, and where

We list each §112 objection with the claim and the page it appears on.

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Questions people ask

A §112(b) indefiniteness objection usually is: it is answered by clarifying language rather than by distinguishing art. A §112(a) written description or enablement rejection can be harder than a prior-art rejection, because the specification is fixed at filing and cannot be supplemented.

No. 35 U.S.C. 132(a) prohibits new matter. You can amend claims and correct obvious errors, but you cannot add description that was not in the application as filed. That constraint is why §112(a) rejections are serious.

Not necessarily. Terms of degree are permitted when the specification or the art gives a skilled reader a reference point for them. Where it does not, either supply the reference point from what the specification already says, or replace the term with a definite limitation.

Where this comes from

Every statement of law or procedure on this page traces to a primary source you can check yourself.

Last reviewed August 30, 2026

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