Never seen such a label before
My 1957-2022 Proof Set Collection Has Been Sold
Have not seen this one.
Jon, can you show the reverse?
Kennedys are my quest...
Is that one of the retro-OGH holders that PCGS was offering?
I believe that@TomB is correct.
PCGS also slabbed their 2021, 35th anniversary commemorative medal in this type of holder.
It too has a lot of info on the label.