I don't know about the dupe codes either. Whenever I key in a two letter airline code to Qube (QF res system) it spits only one company back at me. Grant SYD QF ----- Original Message ----- From: Allan9 <exatc@xxxxxxxxxx> Date: Thursday, August 14, 2003 1:21 am Subject: Re: Piedmont/US Air, Request > I don't know of any duplicated code. Computers aren't smart > enough to tell > the difference by themselves. > Al > > ----- Original Message ----- > From: "Roger & Amanda La France" <lafrance@xxxxxxxxxxx> > To: <AIRLINE@xxxxxxxxxxxxxxxxx> > Sent: Wednesday, August 13, 2003 9:50 AM > Subject: Re: Piedmont/US Air, Request > > > > What if Uncle Joe's Airline and Garage Door Company codeshares > with QX > > on their flight to SDY. Then Uncle Joe's letter code would now > be mixed > > up with David's Big Bad Airline. > > > > -----Original Message----- > > From: The Airline List [mailto:AIRLINE@xxxxxxxxxxxxxxxxx] On > Behalf Of > > David MR > > Sent: Tuesday, August 12, 2003 11:06 PM > > To: AIRLINE@xxxxxxxxxxxxxxxxx > > Subject: Re: Piedmont/US Air, Request > > > > > > Not a dumb question. > > > > There's two codes used for airlines from 3 different > organizations - > > ICAO (International Civil Aviation Organization) uses 3 letter > codes.> The IATA (International Air Transport Association) and ATA > (American> Transportation > > Association) both use 2 character codes. > > > > The 3 letter codes are used on flight plans and other Air Traffic > > Control functions. The 2 character codes are used in airline > > reservation systems, timetables, etc. Originally it was 2 letters > > allowing for up to 676 combinations. Some combinations, I > think, aren't > > used. Once they ran out of 2 letter codes, they went to 1 letter/1 > > number and 1 number/1 letter codes, allowing for even more > combinations.> > > An interesting sideline. It is possible for 2 airlines to have > the same > > 2 letter code, provided the airlines have no possibility of > flying in > > each other's territories. For example, Uncle Joe's Airline and > Garage> Door Company may fly flights with a Cessna 172 in only the > state of > > Arizona while David's Big Bad Airline flies larger aircraft but > flies> only in Australia. The two airlines do not have areas where > both> companies fly so they could be assigned the same 2 letter code. > > > > The plan, at least at one time, was for all airlines to have 3 > letter> codes but that seems to be more of a pipe dream. No one > wants to change > > all the computer programs to accommodate 3 letters. David R > > http://home.attbi.com/~d