In the modern Royal Navy, and other navies of Europe and the Commonwealth, ships are identified by pennant numbers (an internationalisation of the term "pendant numbers" which is what they were called prior to 1948). The name pennant number arises from the fact that ships were originally allocated a flag identifying a flotilla or particular type of vessel: for example, in the Royal Navy, the red burgee for torpedo boats, H for torpedo boat destroyers. By the addition of a number pendant to the identifying flag, each ship could be uniquely identified. A pendant/pennant number thus consists of letters and numbers. Where a letter precedes a number it is known as a "flag superior" and where it is a suffix it is known as a "flag inferior". Not all pendants/pennants have a flag superior.