ELI5: Explain Like I'm 5

Builder's plate

A builder's plate is a metal plate that is attached to the outside of a train, locomotive, steam engine or diesel engine. It contains important information about the machine, such as who made it and when it was made. This metal plate also tells which parts were used to make the machine, as well as the size and weight of the machine. The builder's plate helps people who maintain the machines know how to take care of them and make sure they are safe.