a) A form of low-frequency interference, appearing as a narrow horizontal bar moving vertically through the picture. This is also observed on an oscilloscope at field or frame rate as an extraneous voltage pip moving along the signal at approximately reference black level. b) Slang for visual error, i.e., dropout on tape, spikes at switcher pattern boundaries.

Patterns that jump off screen or any other aberration. c) Slang for a fault in data transmission or other error that does not cause a total lock up.