article_snippet.sent: Cities with similar starting names like Dublin and Dubai caused the labelling to deviate from a regular system, with Dubai adopting DXB, when DUB was already assigned to Dublin.
article_snippet.sent: The triple characters are displayed on luggage tags at airport check-in desks, to ensure The triple characters reach the correct destination.
article_snippet.sent: Many recognise LAX to be the code, but the extra X on the end has baffled travellers for a while, and can be explained by the transition from two letters to three .
article_snippet.sent: The inclusion of an extra letter is the explanation behind the famous LAX code, which was just LA during the 1930s.
article_snippet.sent: Hamad International Airport added the extra X around 1947 to reflect the change in the number of required letters.
article_snippet.sent: Several others similarly adopted the X, which can be seen in airport codes such as PDX for Portland, and DXB for Dubai.
article_snippet.sent: Travellers going to Beijing Capital International may be confused to see PEK on Travellers luggage tags.
article_snippet.sent: However this is from older English spelling of Beijing, which was PEKing .
highlights_snippet.sent: Some follow a pattern like SYD for Sydney and MEL for Melbourne .
  
highlights_snippet.sent: Others don't seem to make any sense, like ORD for Chicago .
  