Originally Posted by Jerry Hill

I think it's missing because the camera does not have manual setting capability. In other words the exposures are the same as 'apeture priority' woud be in a still camera.

There's a bit of guesswork in here but in this mode the camera selects the optimum setting of 'shutter speed' to suit the lighting conditions, there's no iris in the lens so the apeture can not be adjusted.

The only way I know this is that I note that motion blur is lower in bright conditions than lesser light on my video cams, all of which have no manual overrides.