T-Stop means transmission stop. And the other word is transmittance. See https://en.wikipedia.org/wiki/F-number#T-stop
So, one answer could be "people don't even know how to spell it", but OL is not a site specifically for cine lenses and what would you gain by knowing T-stops?
So, one answer could be "people don't even know how to spell it", but OL is not a site specifically for cine lenses and what would you gain by knowing T-stops?