The 36 cards that are not affected are:
● 26 Diamond Kings cards
● 7 checklist cards (although checklist card #600 has its own, unrelated variations previously documented here)
● 2 "Award Winner" cards
● 1 Warren Spahn "puzzle" card
That leaves 624 of the 660-card affected.
The variations occur on the backs of the cards. The copyright info has "LEAF INC" (no period after INC) or it has "LEAF INC." (with a period after INC). Also, in the statistics header, cards can be found with " * Denotes " (1 asterisk) or with " * Denotes * " (2 asterisks). This amounts to 4 variations, which have been limited to these versions:
[a] - VAR: "© 1988 LEAF, INC." & "* Denotes" on back
[b] - VAR: "© 1988 LEAF, INC." & "* Denotes *" on back
[c] - VAR: "© 1988 LEAF, INC" & "* Denotes" on back
[d] - VAR: "© 1988 LEAF, INC" & "* Denotes *" on back
If you have one of the cards that was not previously visually verified, please add a message to the forum thread which is located here. One of the members of the team will contact you for photos or scans.

A very colorful set that was printed on thin card stock. Loaded
with rookies. Griffey Jr., Sheffield, R. Johnson, Schilling and others.
Overproduced and not worth much if anything.

I still think this is one of the coolest card designs of any set! I still love looking at these cards.