Profile Form and Position, Positive Rotation Definition

[[Ja...]]

When creating a profile form and position analysis on an airfoil,   the Zeiss software automatically assigns clockwise as the positive direction for rotation (twist) analysis,  I cannot find anywhere why this is or see any option to change it.   

Can anyone tell me why clockwise is positive (looking down the Z- Axis)? 

[[Jo...]]

Is this a Inspect airfoil special function?

Never used that modul, but there is a free training on youtube.