The Principal System tab displays the geometric properties of a thin-walled section and the sectional properties measured in relation to the principal coordinate system. 
View the parameters on this tab:
- Moments of inertia in the central coordinate system 
  
- Warping constant and centrifugal warping constants 
  
- Maximum distances 
- Vy, Ypy - the distance of the outermost section fibers to the z axis 
 
- Vz, Ypz - the distance of the outermost section fibers to the y axis