In binary-coded data, a condition that is maintained such that, in any permissible coded expression, the total number of 1s, or 0s, is always odd or always even. Note 1: Parity is used in error -detecting and error-correcting codes. Note 2: For example, in the ASCII code or in the International Telegraph Alphabet 5 (ITA-5) code as usually implemented, 7 bits are used to represent each character and 1 bit is used as a parity check bit. 2. Bit (s) used to determine whether a block of data has been altered.