The One-Click-Cargo was replaced with One-Click-Unload (abbreviated: OCU) with the 5 Dec 2016 Game Update. OCU is now available with level 16 for 180 or with level 35 for 90,000;105,000;105,000.
The One-Click-Cargo (abbreviation: OCC) allowed a player to collect from all wagons in a cargo train with one click on the locomotive. In other words, OCC eliminates the need to click on each individual wagon. It was a required upgrade for all locomotives with power of 15 and higher.
At one point, Pixel Federation offered One-Click-Cargo, One-Click-Passenger, and One-Click-Mail for free to new players who played the game via the TrainStation Portal. However, they realized that this made the game unbalanced, and they removed this incentive. Pixel still promotes the Portal as the preferred method of playing the game, using Portal-only content as incentives.