Whiteordinate
Whiteordinate is a brain white matter location.  It is generally represented by a white matter voxel, though in principle, it can also be represented by a surface vertex (node).  Whiteordinates represent a subset of all brainordinates.  In a CIFTI file, a list of whiteordinates need not fill the entire grid of the 'N x M x O' volumetric dimensions.