The abbreviation for the country comes from its Germanic name, which is Fürstentum Liechtenstein, or the Principality of Liechtenstein. There is a movement to change the abbreviation for the car stickers to LI, but that can also be easily confused with Lithuania, although that abbreviation is LT.

The abbreviation for Finland is FIN and for Flanders is VL, which is the Flemish version, Vlaanderen. L is the abbreviation for Luxembourg. The abbreviation for France is most commonly F, but is also seen as FR. These countries are sometimes first guesses at which country the FL designation is for.

Country codes for other continents can be confusing to people who do not know the language of the country.

More Info: en.wikipedia.org