Scott,

Here is the rule book states:

6.5 Scale shall be determined by the wingspan. A change in wingspan will become a change in overall
Scale. Fuselage width, height and aircraft planform or any other variations shall not exceed 10% of scale, with the exception of airfoils and size/shape of control surface within the scale outline rule.

What this is saying from any overall view (outline) of the aircraft in question you are looking at the "planform" of the design, the scale model representation of the full scale should not deviate more than 10% based on the wingspan scale. So you can move wings or tail around up to 10% as well as the width, height and length of the fuselage. The exception is there is no "scale" requirement for airfoils and size/shape of control surfaces as long as they are within overall outline of the aircraft.
Hope this answers your questions.

Tom Wheeler
IMAC Sequence Committee Member
AMA Scale Aerobatic Contest Board Member