An antenna is classified as Dual Slant ±45° polarised if it contains two internal elements operating as a single unit, in which the first and second elements radiate linearly polarised waves whose electric field vectors are 45 degrees clockwise and 45 degrees counterclockwise, when viewed in the forward direction, to the ordinary mounting of the antenna radome.
Single unit is an arbitrary term which may refer to any aspect of the antenna's operation, including but not limited to, operating frequency band, described application, or multiple element technology.
The classification is more restrictive than Dual Linear, but less restrictive than defining individual element polarisations.