Late last month, USPTO Director Kathi Vidal vacated an earlier Patent Trial and Appeal Board (PTAB) determination that Apple and Samsung are real parties in interest (RPIs) in an inter partes review (IPR) filed by Unified Patents against patent holder MemoryWeb. Per Vidal, that RPI determination should not have been made in Unified’s earlier IPR because estoppel does not apply there. Rather, any estoppel (which bars a party from filing PTAB petitions against a patent already challenged by a sufficiently related petitioner)—and thus this RPI determination, if made again—should be left for a proceeding where such an estoppel could properly apply: here, in two follow-on IPRs, in which discovery on the same RPI issues is underway, this time with the participation of petitioners and Unified member companies Apple and Samsung. The PTAB has since posted a public version of its partly reversed March order, arguably previewing where the Board might go yet again by revealing the underlying bases for the earlier RPI decision, including the key role that Unified’s own marketing materials played before.