Offline referral marketers sometimes use trackable business cards. All SafeBoda drivers are identifiable and trackable through their system. The resulting packages are also installable and trackable via Pacman. Enemy shipping, including troop convoys, was thus trackable, exposing it to Allied attack. There is also a geocaching trackable named Kala Pattar Yeti attached near the summit. These transactions are trackable and irreversible. In addition, PMI was legally obligated to mark its products with trackable serial codes. Sometimes the ballots themselves are numbered, making the vote trackable. Human beings in surveyed urban environments are each surrounded by 1000 to 5000 trackable objects. Transformations should be controlled and trackable by background services. The Trackable itself describes the pattern the algorithm should look for in the video stream. For PI to work, the responses must be trackable. According to NASA, as of January 1998, 8 of 285 trackable pieces remained in orbit.