The skew interaction is activated for the current canvas pad by clicking on the Scale tab of the interaction control ( 3.1.3. Interaction Control) in the Control Window.
The scale interaction allows the copying of φ or Z scales between projections. After activating the scale interaction, a scale may be copied by dragging it from the source window into the target window. A φ-scale copy will only work between two projections which have their vertical axes representing φ. A Z-scale copy will only work between two projections which have their horizontal axes representing Z.
The scale interaction does not have a pop-up menu.