base 14 is a positional numeral system with fourteen as its base. It uses 14 different digits for representing numbers. The digits for base 14 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, and d.

base 28 is a positional numeral system with twenty-eight as its base. It uses 28 different digits for representing numbers. The digits for base 28 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, and r.