Systems and methods for encoding and decoding data utilize selective substitution of a conversion table for converting data having a basic data length of m bits into a variable length code (d, k; m, n) having a minimum run of d (d>0), a maximum run length of k and a basic codeword length of n bits, wherein the systems and methods use a basic conversion table and a substitute conversion table for converting the data. The selective substitution of the conversion table in a preferred exemplary embodiment is based on control information of a data string and/or a variable length code string.