In accordance with one or more embodiments data may be encoded into a code word that meets run length constraints and has a reduced running digital sum by encoding (N-y)-1 data bits and y flag bits into m first n-bit patterns that form a first N-bit code word, producing a second N-bit code word by encoding the (N-y)-1 data bits and the y flag bits into m second n-bit patterns in which corresponding first and second n-bit patterns combine to meet a first predetermined running digital sum threshold, and selecting the code word that satisfies selection criteria. The selection criteria may, for example, be the word with the fewest transitions, the word with the smallest running digital sum, and so forth.