Question

To specify the case of letter in text​

Answer 1

Explanation:

Letter case (or just case) is the distinction between the letters that are in larger upper case or capitals (or more formally majuscule) and smaller lower case (or more formally minuscule) in the written representation of certain languages. The writing systems that distinguish between the upper and lower case have two parallel sets of letters, with each letter in one set usually having an equivalent in the other set. The two case variants are alternative representations of the same letter: they have the same name and pronunciation and are treated identically when sorting in alphabetical order.