<P> In typography, a counter is the area of a letter that is entirely or partially enclosed by a letter form or a symbol (the counter-space / the hole of). Letters containing closed counters include A, B, D, O, P, Q, R, a, b, d, e, g, o, p, and q . Letters containing open counters include c, f, h, i, s etc . The digits 0, 4, 6, 8, and 9 also possess a counter . An aperture is the opening between an open counter and the outside of the letter . </P> <P> The lowercase' g' has two typographic variants: the single - story' ' has one closed counter and one open counter (and hence one aperture); the double - story' ' has two closed counters . </P>

White space located inside letters like o and p