Shipping computer login code is a paper note in Fallout 3. It can be obtained from Milo, shipping foreman at the Nuka-Cola plant, either through dialogue or from his corpse. With it, you can access the Nuka-Cola shipping terminal nearby.
Transcript
The password for the shipping computer in the Nuka-Cola Bottling Plant is NC-C1864.
Behind the scenes
The pass code for the shipping computer is the registry number of the USS Reliant in Star Trek II: The Wrath of Khan.