This issue of The PTAB Review begins by summarizing a recent Patent Trial and Appeal Board (PTAB) decision strictly applying the public availability standard for prior art references as a basis for denying institution. Next, we examine a recent appellate decision addressing the ability of a joinder petitioner to oppose a motion to amend that the primary petitioner elects not to oppose. Third, we consider prohibitions against incorporation by reference at the Federal Circuit and at the PTAB. Finally, we summarize recent United States Patent and Trademark Office (USPTO) formal guidance regarding the legal standards for determining obviousness.