I did not say it does; my point was there is no way you could make the confusion of "c=centimeter" because the abbreviation for centimeter is not "c".

The use of "c"-- whether upper or lower case-- in tire sizing designations comes from, as I understand it, the old French system of designation different wheel sizes alphabetically, e.g. 650B, 700C, etc. When referring to a specific tire size, the convention was to append the wheel size letter to the end of the whole string, rather than after the rim size, so we see, for example, 700 x 23C instead of 700C x 23.

In any case, the designation is largely meaningless except, perhaps, to distinguish when you're referring to both a rim inner width (or bead seat width, BSW) and a tire size and need to avoid confusion, for example, "I'm running a 23(C) on a 23(mm), but thinking of moving up to 25 (C)".