We have all seen it, and we know truckers love it. On a daily basis on busy highways there are many truckers or 'HGV's' that display show plates with names or nick names, presumably of the driver. Now this is pretty common across the globe and we assume that these show plates aren't just for the show purposes but for background use in warehouses and loading areas where truck drivers want to know which truck is theirs and only for their use.
These show plates could be displayed for easy identifying of which truck driver is allocated to each truck so when shifts end and start again, going back to the same truck is not as hard reading our every number plate on the long fleet of trucks. Truck drivers like personalising their trucks with things like custom show plates as this is something they use for the majority of the their day and they want to let people know that 'TOM' is driving that truck and he enjoys what he does for a living.
Show plates can have many uses such as creating custom signs for any possible use such as keeping unwanted people off your premises.