\u0013 (C99)\U000013 (C99)\x13 (encoding-dependent)\023 (encoding-dependent)\u{13} (C++23)\x{13} (C++23, encoding-dependent)\o{023} (C++23, encoding-dependent)\U00000013\u0013\x13 (encoding-dependent)\023 (encoding-dependent)\u0013\u{13}\u0013\x13\13\000013=13%13