Vertical Redundancy Check
(VRC) An error checking method performed on one 8-bit ASCII character, where the 8th bit is used as the parity bit.
The resulting parity bit is constructed by XORing the word. The result is a "1" if there is an odd number of 1s, and a "0" if there is an even number of 1s in the word. This method is unreliable because if an odd number of bits are distorted, the check will not detect the error. The Longitudinal Redundancy Check is an improvement.