Code

From Memory Alpha, the free Star Trek reference.

The term code refers to a system of signals for sending messages or to define a situation.

Such codes may include:

• Code One alert, indicates a declaration of war or other disaster.
• Code 2, an encryption format broken by the Romulans.
• Code 3, an encryption format unbroken by the Romulans.
• Code 47, pertains to a message "for captain's eyes only".
• Code 710, a warning to not approach a planet.
• Code 1-Alpha-Zero, indicates a ship in distress.
• Code Factor 1, indicates a possible invasion.
• Code blue, used to indicate a change in starship flight status.
• Code White resuscitation, used to indicate the need to resuscitate a dead individual.
• Chess code, uses chess moves as signs and countersigns in communications.
• Emergency Code 1, indicates intruder alert.
• Interstat code, a 21st century communications code.
• Transporter Code 14, issued to destroy object in transporter beam.

A code may also refer to a language:

• Binary code, computer language predating trinary code.
• Trinary code, computer language following binary code.
• Morse code, antiquated means of communication via telegraphs.

In addition, a code may also refer to a password to access critical ship systems:

• Command authorization code
• Prefix code

As well, a code may also refer to the various signals used by a series 5 long-range tactical armor unit:

• Confirmation code, used by the Strategic Command Matrix to validate new orders.
• Infiltration code, believed to be used by the enemy on Salina Prime to interrupt a Unit's mission.

Code may also refer to:

• "Code of Honor", a TNG Season 1.