The location of a feature is specified as one of the three methods listed below
XYZ on the face: The feature is aligned so that its depth is aligned with the –Z direction of the setup. It is positioned by giving the X, Y and Z coordinates in the plane of the setup.
Polar on the face: The feature is aligned so that its depth is aligned with the –Z direction of the setup. It is positioned by giving a radius and angle.
Polar on the OD: The Radius specifies the distance of the feature from the Z axis. The Angle is the counter clock-wise angle, in degrees, from the X axis. The Y distance is distance the feature is translated from the radius. The Z coordinate is the distance the feature is translated in the Z direction. This option is only available for 4th axis indexing or turn/mill documents. See also 4th axis indexing with a single setup - Positioning features.
See also Feature_wizard and Relative Position.