Jacob Fryxelius, designer of Terraforming Mars, reveals some of the easter eggs hidden in Terraforming Mars in this weekly article series.
Mining Guild
As with Tharsis Republic, the Mining Guild is not a typical corporation, but rather a cooperative of smaller actors in the mining business. This of course makes no difference in the game.
Its logo is a Mars symbol with a drill into Mars, alluding to metal exports from Mars.
In contrast to CrediCor, which has a lot of business on Earth, the Mining Guild logo can be seen in cards such as Rover Construction, Carbonate Processing, Mining Rights, and Power Supply Consortium.
UNMI
Being an extension of the World Government, the United Nations Mars Initiative will initiate terraforming before other corporations are ready to step in.
Its logo and color scheme is very similar to the UN logo, but with a mesh between an Earth and a Mars symbol, indicating its intent to make Mars earthlike. This symbol is very similar to the terraform rating icon, as well as the Terraforming Committee emblem.