 Most major airlines use the alphabet to communicate passenger name records (PNRs) internally, and in some cases, with customers.It is often used in a medical context as well, to avoid confusion when transmitting information.Several letter codes and abbreviations using the spelling alphabet have become well-known, such as Bravo Zulu (letter code BZ) for "well done", Checkpoint Charlie (Checkpoint C) in Berlin, and Zulu Time for Greenwich Mean Time or Coordinated Universal Time.