A record medium, such as a magnetic tape, optical disk, magnetic disk, and the like stores data signals and error redundancy signals. Re-synchronisation signals are interleaved between the recorded signals such that the error redundancy signals are usable to correct signals recorded between such interposed re-synchronisation signals wherein no error redundancy signals are recorded. Error pointing redundancy signals are recorded between all of the re-synchronisation signals for pointing to signals in error for enhancing the error correction. Such error pointing signals can be cyclic redundancy check (CRC) signals. Controls for taking advantage of the above-described arrangement are also described. Reframing and clock synchronisation controls are also disclosed.