Section 102(b) of the American Invents Act provides two exceptions to prior-art provisions of 102(a)1: A disclosure made 1 year or less before the effective filing date of a claimed invention shall not be prior art to the claimed invention under subsection (a)(1) if--

‘(A) the disclosure was made by the inventor or joint inventor or by another who obtained the subject matter disclosed directly or indirectly from the inventor or a joint inventor; or

‘(B) the subject matter disclosed had, before such disclosure, been publicly disclosed by the inventor or a joint inventor or another who obtained the subject matter disclosed directly or indirectly from the inventor or a joint inventor.

Under the interpretation of §102(b)1(B) proposed in the USPTO Examination Guidelines for Implementing the First-to-File Provisions of the AIA, http://www.gpo.gov/fdsys/pkg/FR-2012-07-26/pdf/2012-17898.pdf (published July 26, 2012),

the subject matter in the prior disclosure being relied upon under 35 U.S.C. 102(a) [must] be the same ‘‘subject matter’’ as the subject matter publicly disclosed by the inventor before such prior art disclosure for the exception in 35 U.S.C. 102(b)(1)(B) to apply. Even if the only differences between the subject matter in the prior art disclosure that is relied upon under 35 U.S.C. 102(a) and the subject matter publicly disclosed by the inventor before such prior art disclosure are mere insubstantial changes, or only trivial or obvious variations, the exception under 35 U.S.C. 102(b)(1)(B) does not apply.

This interpretation leaves little “grace” in the 1-year grace period. An applicant will be able to overcome a later prior-art publication only as to subject matter that was specifically disclosed in its earlier disclosure. Thus, if the applicant discloses A, B, and C within a year of filing, and a later, pre-filing references discloses A, B, C, and D, a claim to A, B, C, and D, would presumably fail under 102(a)(1).

The rule, though harsh, is analogous to current practice in the EPO on subject matter support in a claimed priority document: Unless each limitation of a claim in an application finds support in the priority document, the claim will lack novelty over an intervening reference that discloses all of the claim limitations.