Class A planets are inhabited planets controlled by a Type II civilization.
Class B planets are inhabited planets controlled by a Type I civilization.
Class C-1 are uninhabited planets perfect for colonization. These planets have the highest chance of success with colonization attempts. These planets usually contain life, but no intelligent life.
Class C-2 planets are uninhabited planets that are good candidates for colonization. These planets have good, but lower chances of success with colonization attempts. These planets usually contain only plant life.
Class C-3 planets are uninhabited planets that are candidates for colonization. These planets have the lowest chances of success with colonization of all Class C. These planets usually contain no life, but contain water and will easily sustain life.
Class T-1 planets are uninhabited planets containing no life. These planets are the prime candidates for terraforming, and have the highest chances of success.
Class T-2 planets are uninhabited planets containing no life. These planets are the secondary candidates for terraforming, and have a lower chance of success than T-1 planets.
Class R planets are uninhabited planets containing no life. These planets contain many natural resources and are prime for mining.
Class Y planets are planets that contain possible scientific discoveries and should be researched.
Class G planets are planets containing some sort of space anomaly, usually one that breaks our theories of the universe. These planets are occasionally dangerous.
Class D-1 planets are potentially hazardous planets. These planets should be avoided.
Class D-2 planets are hazardous planets. These planets are banned from visiting.
Class D-3 planets are hazardous planets that need to be stayed away from at all costs.
Class U planets are unsurveyed planets that have not received a class yet.
To: Of the Galaxy