In the UK every car has a unique registration number, currently this registration mark is made up a mixture of numbers and letters. The registration number format is broken down into 3 sections, the first two letter tell you where the car was first registered, this is also known as the memory tag.
After the two letters on the car registration there are two numbers, these numbers identify the date in which the car was registered. In the UK there are two period in which new cars are registered this is in March to August and then again in September to February. So a 53 on the number plate indicates a 2003 registration and a 60 plate would be a September 2010 date. The last 3 letter do not represent anything and are just random letters.
As every car is assigned a unique combination of numbers and letters this means that information can be held to identify a car. From the plate by accessing the database you can tell the make, model and even colour of the car. Your number plate has to be displayed correctly, any modifications are illegal. If you ever need a plate making up you have to go through a registered number plate supplier. There are very specific specifications and requirements for how your car registration has to be displayed.
As each car has information recorded on it which is stored on several different databases this information can be accessed by licensed authorities. There are companies that bring all of this information together from the different databases to provide reports to people seeking this information. Typically these are provided as car registration check reports that can be obtained from several specialist companies for a small fee. The information is useful to individuals wanting to find out about a used or second hand car that they may be interested in purchasing.