A measurement technique to align content acquired at 60 Hz (30 frames per second) with NTSC transmission of 29.97 fps. Content is acquired and edited at 30 fps, but two frames are dropped every two minutes, to yield an overall 29.97 fps for broadcast of 30 fps content.

A type of time code designed to match the real time of clocks. Two frames of time code are dropped every minute, on the minute, except every tenth minute. This corrects for video frames that occur at [..]

American system of time code generation that adjusts the generated data every minute to compensate for the spread of the NTSC television system running at 29.97 frames per second.

A trailer frame that drops downward to increase cargo capability without increasing the vertical clearance of the vehicle.  Consists of two types:  single drop and double drop.