Thank you for taking the time to respond.
HOWEVER - the original question was, and also my above question is - in relation to DATES - namely, changing 1st, 2nd, 3rd, 4th, 5th, etc .... into superscript suffixes.
IF we were to attempt to do this in the function System Preferences > Keyboard > Text - using "replace" / "with" - you would have to set up well over 100 of them - because I have ALREADY TRIED.
And setting up 1st only works with "1st" - it does not with with 21st, 31st, 41st, etc ....
So, you would have to set this up for every single number in the world. Not very convenient.
The function - System Preferences > Keyboard > Text - is only really designed to work for things like(tm), (c), etc .... and also for fractions like 1/2, 1/4, 1/3.
it does not really work for numerical suffixes in the DATES context.