While searching for symmetric profiles I stumbled across different definitions (point-clouds) of the NACA 642-015A profile.
The figure below (skewed) shows the difference in percent chord on the secondary axis (green markers).
What causes these differences and is there a analytical description I could use to create a point-cloud with higher resolution.
Another question is: The NACA Reports I could find via Google all feature the NACA 642-015 (without the "A"). The difference between NACA 642-015A and NACA 642-015 is an increased thickness of the A-version towards the trailing edge. Who introduced or developed the A-version?