After choosing the target (if applicable), the Cargo Transfer window displays the unit you started with on the left, and the target on the right.

  • Up, Down: Choose kind of cargo to transfer
  • Left, Right: Move 10 units. With prefix argument, move that many
  • ShiftLeft, ShiftRight: Move 1 unit
  • CtrlLeft, CtrlRight: Move 100 units
  • AltLeft, AltRight: Move as much as possible. With prefix, move as many to make the left/right unit have exactly that many.
  • U: If one unit is a planet, move all T/D/M/$/Sup/Colonists to that unit
  • S: If one unit is a planet, toggle automatic supply sale. Supplies you move off one unit appear as megacredits on the other

Reference

Keys:
C and U from control screens and visual scan
This is a testing version.
It may be incomplete, and have more bugs (or features) than the public live version at planetscentral.com.