4 modes are available for selecting a position on a scan:

• Scan Point: Selects the nearest facet point within the snap radius.
• Scan Edge: Selects the position on the nearest facet edge within the snap radius.
• Scan Facet: Selects the exact selection position.
• Scan Auto: Automatically selects the nearest point within the snap radius or the position on the edge or facet.
   

Those modes give a better precision while creating geometries on top of a Scan Data.

NB: No need K72 Scan Modeling to get this capability