Naval constructors designed around treaty accounting

British constructors could find extra wartime aircraft capacity because treaty-era designers were adept at exploiting accounting rules. Examples include water tanks in the Illustrious design that could later hold fuel, space in County-class cruisers ready to accept additional belt armour, and water counted as protection in Rodney and Nelson. These practices do not make displacement limits meaningless. They show how architects designed future flexibility into the categories the treaty measured, supporting the possibility that a scout carrier sized for twenty-four large TSR aircraft could squeeze in additional fighters when war demanded it.