A numeral denotes (stands for) an integer. '123', '0123', '00123' are numerals that all stand for the integer 123 (base 10).

Bases -16, ..., -2, and 2, ... 16, are allowed, e.g., try base -10; each digit must be less than |base|. Digits are {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F}.