At the USPTO, the typical appeal procedure is for an applicant to file a notice and then the substantive Appeal Brief, where the examiner then files an Answer. The Applicant also has the optional ability to file a Reply Brief, enabling the applicant to have the last word before the case is transferred to the Board for an optional hearing and then decision. As discussed in previous posts, the PTAB will not consider new arguments in a Reply Brief unless good cause is shown.

Despite the limits on a Reply brief and the fact that it is optional, applicants should think carefully about skipping it. The “gotcha” mentality of administrative agency decision makers knows almost no limits as we see in a recent appeal by Intel.

The case is Appeal 2020-003597, Application 15/650,230. The invention relates to a method for caching storage management to support guest instruction to native instruction conversion. Claim 1 is reproduced below:

1. A method for caching storage management to support guest instruction to native instruction conversion, the method comprising:
accessing a set of guest instructions from guest code;
translating the set of guest instructions into a set of native instructions;storing the set of native instructions in a native instruction cache;
storing mappings between an identifier based on a guest address for the set of guest instructions and an identifier based on a native address for the set of native instructions, the mappings being stored in a conversion look aside buffer; and
storing the set of native instructions in a hierarchical cache where the set of native instructions are removed from the hierarchical cache based on a least recently used replacement scheme.

In the Appeal, Intel argued that the secondary reference (Mallick) disclosed a translation lookaside buffer (TLB) as opposed to the recited conversion lookaside buffer. Intel also focused on the distinction between address translation and instruction translation.

While the examiner relied on Mallick’s TLB, the examiner’s Answer included some cryptic language that when the secondary reference(Mallick) was combined with the primary reference (Agarwal), the combination rendered the claimed features obvious, including the use of a conversion lookaside buffer.

Intel’s appeal brief did not specifically and clearly address the examiner’s new position. And Intel did not file a reply brief, likely because they felt that the “clarified” reasoning of the Examiner in the Answer illustrated the weakness of the rejection and was unsupported by any evidence. However, the PTAB flipped the issue on its head and found that because Intel did not dispute the new reasoning by the Examiner in the Answer, the Examiner’s reasoning stood effectively unrebutted.

Additionally, although a Reply Brief is not required, Appellant did not file a Reply Brief and failed to address the Examiner’s clarified findings and additional discussion of Agarwal and Mallick and the disputed limitations of claim 1, or otherwise rebut the findings and responsive arguments made by the Examiner in the Answer. See Ans. 5–13. Accordingly, based on a preponderance of the evidence, Appellant’s contentions do not persuade us that the Examiner erred in concluding that Mallick (in combination with Agarwal) teaches the disputed address mappings.

As can be seen, the PTAB will often take silence as an effective admission and that can be enough for the examiner’s reasoning to be accepted. So, while not required (and while the PTAB will generally not consider new arguments not raised in the appeal brief), a Reply Brief can be an important tool where the examiner presents new (or “clarified”) explanations in the Answer.