Found this by accident. RCA technical papers / articles. Searchable.. interesting, thought it might be of interest to all.

https://www.americanradiohistory.com/RCA_Review_Issue_Key.htm

Very cool. Thanks for sharing.

I like how between the years 1968 and 1972 they list the year "9626"...If I click on that will it start playing the song "in the Year 2525"? :D

https://www.youtube.com/watch?v=izQB2-Kmiic