Why does PCGS List 1970 Mint Sets as having a small and large date?

Is this just an error, or has their been new discoveries? I knew of the 1970 S lg/sm date Proof Sets, but not Mint Sets. Any reason to open my 1970 Mint Sets?
Jim
When a man who is honestly mistaken hears the truth, he will either quit being mistaken or cease to be honest....Abraham Lincoln
Patriotism is supporting your country all the time, and your government when it deserves it.....Mark Twain
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Comments
Redbook 2022, pg 362, has the uncirculated mint set listed w/both large and small date cent.
USAF veteran 1984-2005
There are S cents in the Mint set.
This
Oooooh! Haven't opened mine and had forgotten that 68-74 had S. Thanks for allowing me to remember.
Jim
When a man who is honestly mistaken hears the truth, he will either quit being mistaken or cease to be honest....Abraham Lincoln
Patriotism is supporting your country all the time, and your government when it deserves it.....Mark Twain
I have several mint sets with the small date cent.