Cecil’s answer of decades back was correct as far as it went, but the truth is always stranger than fiction. My brother-in-law Paul was working back then for an electronic company in R & D when they were approached by a railroad company (I think, but am not sure, Union Pacific) to come up with a sensor box and hookups to replace the caboose. Paul had worked for years on auto-pilots for small airplanes and had some good ideas. He soon had the electronics figured to go in the box on the back car coupler, but needed an enclosure. So he made a model out of cardboard at home, which my neices and nephew played with until he found an aluminum fabrication company in Colorado who would make the prototype. He took the model away from the kids and UPS’ed it out there. The model was handed over to my brother, also named Paul, who fabricated the first enclosure and took the model home and let that set of neices and nephews play with it.
The railroad was pleased and ordered the devices into production. The engineers immediately made up their own name for the box perched on the back coupler… F***ing Rear End Device or F.R.E.D. It could only happen in America.