Short for vertical redundancy check it is a method of error checking that attaches a parity bit to each byte of data to be transmitted,which is then tested to determine if the
transmission is correct. This method is considered to be somewhat unreliable. If
an odd number of bits are distorted, the check will not detect the error.
VRC (vertical redundancy check) is synonymous with TRC (transverse
redundancy check).
IBM Bisync Block Checking Procedures In this method, both a Vertical Redundancy Check (character parity) and a Longitudinal Redundancy Check (block parity or horizontal parity) are performed. The VRC bit provides odd-parity for each character. The LRC provides odd-parity of each bit position of all characters in the block.
