The selected excerpts from the PTAB’s decision are copied above. So, how the party (Jung, a.k.a. Samsung Electronics) responded to the PTAB’s decision? How the claims at issue were amended?

In the response (dated 5/22/2017), the Applicant had significantly amended claim 1 and removed “at least one of a connection branch or a contents connection list[.]” The Examiner subsequently rejected the claims over the prior art. The Applicant further amended claim 1 (without reciting “at least one of …”). The prosecution continued. The final allowed claims did not recite any feature of “at least one of A or B.”

And, the following are (so-called) practical guidelines from https://www.finnegan.com/en/insights/blogs/prosecution-first/informative-one-day-non-informative-the-next.html

Prosecution Takeaway:  SuperGuide and Jung demonstrate how the patent drafter’s selection of words, even seemingly minor ones, may have a significant impact on how a claim is construed or whether it is found patentable. When drafting patent applications with the phrase “at least one” followed by a list, not set apart by a noun, using “and” in the list means the claim will be construed conjunctively to require each item listed because “at least one” modifies each category in the criteria list.

For example, per SuperGuide, “at least one of a W, a X, a Y, and a Z” will require at least one W and at least one X and at least one Y and at least one Z.

To encompass a scenario where only one of the items listed is required, the practitioner could use “or” instead of “and.” That was PTAB’s proposal 1) above.

As variation, practitioners may end a list with “and/or” instead of “and” or “or”, e.g., “at least one A and/or at least one B.” But practitioners should be sure to describe an “and/or” example in the specification to include both the “and” scenario and the “or” scenario, to support the desired claim construction.

A more conservative approach might be to recite “At least one widget chosen from A widgets and B widgets.” This construction should render unnecessary the use of “mixture” in the following list:  “At least one widget chosen from A widgets, B widgets, and mixtures thereof.”

Another approach is to present an independent claim to embodiment 1 (at least one A widget) and another independent claim to embodiment 2 (at least one B widget). Two independent claims insures a claim to A widgets alone and another to B widgets alone.

None of the examples above suggests using “at least one widget selected from the group consisting of A widgets and B widgets.” This is because such a Markush group (using “consisting of”) may be construed to mean that the claim is closed to any widget other than A and B widgets.  See. e.g., Multilayer Stretch Cling Film Holdings, Inc. v. Berry Plastics Corp., 831 F.3d 1350 (Fed. Cir. 2016).