The minuscule (lower-case) form of 'd' consists of a loop and a tall vertical stroke. It developed by gradual variations on the majuscule (capital) form. In handwriting, it was common to start the arc to the left of the vertical stroke, resulting in a serif at the top of the arc. This serif was extended while the rest of the letter was reduced, resulting in an angled stroke and loop. The angled stroke slowly developed into a vertical stroke.