A system in which encoded data (e.g., encoded video and auxiliary data) are transmitted over a serial link. Other aspects of the invention are transmitters for use in encoding data for transmission over a serial link, receivers for receiving such data, and methods for sending encoded data over a serial link. Source data to be transmitted are encoded using a subset of a full set of code words. The subset consists of preferred code words. Disjoint clusters of code words in the full set are predetermined. Each cluster includes one or more of the preferred words, and optionally also at least one additional code word that is similar to a preferred word of the cluster in the sense that it is likely to be generated as a result of probable bit errors in transmission, or transmission and decoding, of such preferred word. Each preferred word of a cluster is indicative of a single source data value. Each received code word in a cluster is mapped to the source data value determined by each preferred word of the cluster.