1941-S Lincoln M.m. Question

It's just small and large S - the only 'micro S' in 20th century coinage is the 1945S dime.

The small S 1941 cents are more common than the large S, but not enough so that the large S deserve much premium. So far no major guide lists the difference because it would be a waste of a line. The ratio of small S to large S in my studies has been about 10 to 1.

There were at least three different S mintmarks used on 1945S dimes...this one was smaller than the small mintmark, so they called it the micro mintmark.

1941S cents only have two sizes - large and small.

It's a simple matter of nomenclature that stuck. There is no hard and fast rule as to what a mintmark has to be to be called a micro mintmark...but calling any 20th century coin a micro mintmark other than the 1945S dime would confuse people since that's the only issue that carries the name.