Reed–Solomon error correction
Finite fields are used by many error correction codes, such as Reed–Solomon error correction code or BCH code. The finite field almost always has characteristic of 2, since computer data is stored in binary. For example, a byte of data can be interpreted as an element of formula_34. One exception is PDF417 bar code, which is formula_35. Some CPUs have special instructions that can be useful for finite fields of characteristic 2, generally variations of carry-less product.