Was HMS Unicorn an auxiliary or an aircraft carrier?

Did HMS Unicorn count against aircraft-carrier displacement under the treaty?

It was debatable: Henderson could argue that her maintenance mission and auxiliary-like characteristics kept her outside the carrier category.

Admiral Henderson described Unicorn as a forward fleet aviation support ship, emphasizing aircraft maintenance rather than primarily operating an air group. Her 24-knot design stayed below an auxiliary speed threshold, and the original lack of armor also supported that reading. Protection added during construction complicated the case, as did the ship's obvious ability to operate aircraft. The classification shows how mission language, design intent, and technical thresholds could be used to navigate treaty categories.