Some DTVs will convert the 18 ATSC formats into 1 or 2 formats and will draw only those. For these sets, the 'native' format is: 1. The formats the set will draw or 2. The original format. (These are contradictory definitions, but they reflect current practice. 1 is probably the preferred meaning.)
Proprietary file format of a given application. A format which is not intended to be opened by any other application and is usually unsuitable for transferring data from one application to another.
is a format of the voxels as they are store on the disk, for example, INTENSITY.