By Adam Fowles ( January 4, 2019, 2:02 PM EST) -- The Federal Circuit has affirmed that a Rule 36 judgment may serve as a basis for collateral estoppel in Patent Trial and Appeal Board proceedings, in addition to district court proceedings. In VirnetX Inc. v. Apple Inc.,[1] the Federal Circuit affirmed the PTAB's determination in two inter partes reviews that a prior art document was a printed publication. While the PTAB's final written decision did not reach the merits of any collateral estoppel argument,[2] the Federal Circuit affirmed the PTAB's determination in those two IPRs that a prior art document was a printed publication expressly on the basis of collateral estoppel in view of a Rule 36 affirmance.[3]...