When no CAD is available for reporting Cloud to CAD, in particular on manual CMM's, CMM-Manager offers a solution to report an actual point that was not measured in precisely the correct 3D location by projecting that point to a position directly above the nominal point.  The error can then be reported along the nominal vector of the point as shown here.

If CAD is available, Cloud 2 CAD will always be more accurate, especially if a Cloud Best Fit is done before output.

T Value will always have a small amount of error due to the surface deviation between where the point was actually taken and the surface at the nominal location.  The worse the local surface deviation, and the farther the actual point was taken from the nominal, the greater this error may be.