The optional turnedV attribute shows if the v direction of the cylinder must be inverted. A value of 1 (or true) means the v direction must be inverted. A value of 0 (or false) means the v direction must not be inverted.
Source
<xs:element name="Cylinder23Core" type="Cylinder23CoreType" substitutionGroup="SurfaceCore"><xs:annotation><xs:documentation>The global Cylinder23Core element is the mathematical core of a cylindrical surface.</xs:documentation></xs:annotation></xs:element>