Only the first letter of this sentence is majuscule, the rest being minuscule, or lower case. This is of course a term that applies only to bicameral scripts -- scripts that use two separate cases, which is far from all writing systems, though it is in the modern Latin alphabets. Originally, majuscule and minuscule forms were separate scripts, two of several, and it is only around the time of printing presses that two forms started to be mixed, for clarity, now that letters could me made much smaller and still be legible. Interesting, the "case" of upper case and lower case was originally physical: at a printer's compositing station, the drawers or cases that held majuscule letters was above those that held the miniscules.
His signature consists of two flourishing majuscule letters followed by a slightly wavy line.