Landing Aids question to committee

section 11 of the rules states that "Pilots may not use artificial (not true to their aircraft) gauges or tricks to enhance their vision or their ability to approach an airport." the night vision part of it is fine, but the second part is a bit more troublesome.  

if i have a HUD it increases the ability  to approach an airfield, the tiger cat has one. even though it is not originally part of the realworld aircraft.

so if for example i add a HUD to a mustang, is that considered to be a aid for landing in the sense of article 11?  or is it intended to rule out auto landing and nightvision only.

best regards

Leon