This option defines the load level used when checking the lateral buckling condition. It is available by clicking the appropriate button in the Lateral Buckling Parameters field in the Member Definition - parameters field.
To define a lateral buckling condition, the load application level is needed. You must specify the ordinate of the height where loads are applied in the coordinate system of axes of the bar cross-section. Assuming that lateral buckling occurs when loading a bar in the XZ plane, enter only one coordinate. It is a relative value of the interval <-1.0,1.0>. If a load is applied at a characteristic point of the section (lower shelf, upper shelf and so on) just select the appropriate button and the coordinate value is automatically accepted.