Abstract: A method, computer program product, device, and tracking system for assigning marker identities to markers of a tracker are provided. The tracker includes a reference detectable in a visible light spectrum, and the markers are detectable at least in an infrared light spectrum. The markers are arranged in a pre-determined relationship relative to the reference and the pre-determined relationship is indicative of the marker identities. A method implementation includes receiving first image data of the markers captured in the infrared spectrum. The method further includes receiving second image data of the reference captured in the visible light spectrum. The first and second image data may be captured under at least essentially the same viewing angle. The method further includes assigning the marker identities to the markers determined in the first image data based on the reference determined in the second image data and the pre-determined relationship.