The Machine assigns colored boxes to categorize the individuals, vehicles, watercraft and aircraft it observes, but not animals. These can change as it re-assesses them and are not assigned to all individuals, vehicles, etc.
|White box: Monitored individuals.|
|White box with red corners and crosshairs: Irrelevant threats.|
|Red box: Relevant threats, or threats to the Machine or its Admin.|
|Yellow box: Individuals who know about the Machine.|
|Black box with yellow corners and crosshairs: Individuals designated "Analog Interface". The only known example is Root.|
|Blue box: Individuals designated "Asset Catalyst" or "Catalyst to Asset".|
|Blue box with white corners and crosshairs: The President of the United States, Relevant-One.|
|White box with solid vertical lines and a central target: Monitored vehicles.|
|Yellow box with solid vertical lines and a central target: Vehicles whose passengers all know about the Machine. (“The Devil's Share”)|
|Red box with solid vertical lines and a central target: Vehicles whose passengers are all relevant threats, or a threat to the Machine or its Admin. (“YHWH”) (“ShotSeeker”) (“The Day the World Went Away”)|
|Blue box with solid vertical lines, white corners and a central target: Vehicles carrying Relevant-One. (“Synecdoche”)|
As of Season 3, these boxes have solid vertical lines and a central target.
|White Diamond: Boats, ships and ferries. (Seasons 1, 2 and 4 (flashbacks) (“If-Then-Else”))|
|As of Season 3, these have solid lines from the left and right corners to the crosshairs above and below them, and a central target. In Season 5, the central target disappears. (“Sotto Voce”)|
|Green Triangle (flight number and airport codes also displayed): Airplanes and helicopters under normal operation.|
|Red Triangle: Airplanes under imminent threat, or transporting software considered a threat to the Machine. (“4C”) (“RAM”)|
The Machine has also designated aicraft with white triangles in it's transitions.
Boxes by Season
“Liberty” – present
- The Machine prioritizes threats over other designations as seen in “Wolf and Cub”, “Lethe” and “SNAFU”. In “Wolf and Cub”, Reese, usually assigned a yellow square as he has knowledge of the Machine, and Fusco, usually assigned a white square as he doesn't, were assigned red squares when the Machine learnt they were investigating Finch.
- The scope of the blue box is unclear, as it includes government agents acting on relevant numbers as "direct catalysts" without knowledge of the Machine, such as Michael Cole. However, one doesn't need to work for the government to be assigned the box, as is the case with Shaw. Though her ties to the government were severed, she kept the box as a "catalyst to asset", assisting Finch and Reese. Others who worked on the Machine's behalf were given white boxes. (“Relevance”) (“Trojan Horse”) (“Zero Day”)
- In simulations, boxes are normal unless the simulation is simplified and the boxes are as well. (“If-Then-Else”)
The Machine recognizes celestial objects such as Mars or the Moon, and marks them with their astronomical symbol. (“God Mode”)
The Machine identifies television antennas. (“Baby Blue”)
The Machine codes potential terrorist targets such as sky lanes, shipping lanes and major railroads in white or red. (“Dead Reckoning”)
The Machine identifies subway trains and marks their name, route number, total number of passengers and number of violent threats. It monitors the walkway edge of the subway as a high priority area and codes it with a bold red and white line, while the train is running. When it stops, the Machine adds a chevron to mark the direction the train is moving. (“Brotherhood”) (“If-Then-Else”)
High Priority Subject
High priority subjects are placed in concentrated monitoring and in a similar graphics configuration, their travel trajectory is marked. This has only been seen with the Presidential motorcade carrying "Relevant-One". (“Synecdoche”)
High-Priority Areas are placed in concentrated monitoring. The Machine has identified four High-Priority Areas:
- The White House (“Synecdoche”), featuring :
- a label indicating "Relevant-One" is present
- an outside perimeter marked "restricted"
- a two-dimensional red orbit above, used to denote restricted airspace
- The U.S. Capitol (seen only while MPOV is switching to Washington D.C.)
- The Pentagon (seen only while MPOV is switching to Washington D.C.)
- The National Security Agency (seen from MPOV twice) (“Synecdoche”)(“.exe”), featuring:
- a perimeter coded with concentric red lines forming a wall around the structure
- a two-dimensional red orbit used to denote restricted airspace
The Machine provides the POV for all flashbacks except in:
- “Many Happy Returns” and “Terra Incognita” (Reese)
- “Beta” and “The Cold War” (Samaritan)
- “B.S.O.D.” (Finch & Fusco) (a flashback to Grace is briefly seen through MPOV)
When neither ASI provides a flashback, it is implied it exists in the mind of the respective character.
In flashbacks, the Machine reviews footage in the present, assigning boxes according to a person's status in current time, not at the time, as the producers' commentary (Season 1 DVD) confirms. There are exceptions:
- In a flashback, Denton Weeks has a red square; in the present, a yellow one. (“Super”)
- In a flashback, Reese and Stanton have a red square; in the present, a yellow one and a white one respectively. (“Matsya Nyaya”)
- In flashbacks, Shaw has a white square; in the present, a yellow one. (“Razgovor”) (“The Devil's Share”)
- In a flashback, Finch has a red square (“Prophets”); in another, a white square with red corners and red crosshairs (“Karma”); in the present, a yellow one.
In all cases but Shaw's, the Machine prioritizes threats over other designations (as mentioned earlier):
- In Finch's flashback in “Prophets”, he poses a threat to the Machine.
- In Finch's flashback in “Karma”, he poses a threat to Alicia Corwin.
- In Reese and Stanton's flashback in “Matsya Nyaya”, they are indirect threats to the Machine.
- In Weeks' flashback in “Super”, he poses a threat to the Machine.
In most flashbacks, the Machine assigns squares as they would have appeared at the time (the evolution of the squares can be seen under "Squares by Season"). There are anomalies:
- In a flashback, the ferries are assigned a box from Season 1, while Finch is assigned the yellow square from Season 4. (“If-Then-Else”)
- In a flashback, Finch is assigned a yellow box from Season 2, even though, at the time, the Machine couldn't properly perceive time. Also, due to a facial recognition error, incorrect boxes were assigned to several characters.(“SNAFU”)