(LRC, Block Redundancy Check) An error checking method that generates a longitudinal parity byte from a specified string or block of bytes on a longitudinal track. The longitudinal parity byte is created by placing individual bytes of a string in a two-dimensional array and performing a Vertical Redundancy Check vertically and horizontally on the array, creating an extra byte. This is an improvement over the VRC because it will catch two errors in the individual characters of the string, beyond the odd errors.