Lowercase letters were therefore not interleaved with uppercase. For instance, uuencode uses uppercase letters, digits, and many punctuation characters, but no lowercase. I are separate letters, each with its own uppercase and lowercase forms. I are separate letters, each with its own uppercase and lowercase form. Dictionaries may use lowercase, uppercase, or both. Uppercase is public and lowercase is private. The letter occupies the Unicode slots U+03C4 (lowercase) and U+03A4 (uppercase). Uppercase umlauts were dropped because they are less common than lowercase ones (especially in Switzerland). In mathematics texts it is customary to denote permutations using lowercase Greek letters. Capital letters are typically treated as equivalent to their corresponding lowercase letters. It was written in one stroke, somewhat like a cursive lowercase "e". It is generally denoted (the Greek lowercase letter gamma). Use of the apostrophe may be recommended only for lowercase letters. Suffixes, in form of lowercase letters and figures, further differentiate the master horizons. Capital and lowercase letters were not distinguished in old manuscripts.