A new simple encoding technique that allows the design of almost all known block runlength-limited error control codes is described. Attention is focused on the most widely used codes (Hamming, Reed-Muller, Golay) with RLL properties. The trellis design procedure for the proposed codes is introduced. It is shown that the trellises of the designed codes are similar to the trellises of the coset codes designed by Forney (1988), and provide low-complexity soft maximum-likelihood performance.