TARDIS were not, its weight would shatter the Earth's surface. In the tie-in novels, the interior of the TARDIS has been known to contain an entire city, encompass an entire parallel Earth, and even dwarf Gallifrey itself when turned inside out. A distinctive architectural feature of the TARDIS interior is the roundel. In the context of the TARDIS, a roundel is a circular decoration that adorns the walls of the rooms and corridors of the TARDIS, including the console room. Some roundels conceal TARDIS circuitry and devices, as seen in the serials "The Wheel in Space" (1968), "Logopolis", "Castrovalva" (1981), "Arc
Royal Air Force roundels and upper wing type Bs were also modified by over-painting the red centres in white. The red fin stripe was also painted out with white and, in many cases the blue was extended forward 1 inch making equal widths of . RAAF Mk VIIIs had their roundels and fin flashes modified in the same ways, although some had their upper wing roundels overpainted and replaced with SEAC roundels. All Royal Air Force aircraft carry a flash on the fin. This is either red/white/blue, or red/blue on camouflaged aircraft, with the red stripe nearest the leading edge. Aircraft painted anti-flash white