Boeing has a list of Codes for all airlines to make every customer unique but not Boeing 787

This code is in the form of a two-digit/ letter which will appear after the Aircraft model

for example, Boeing 777-337(LR) for Air India here last two digits 37 is the code of Air India.

condition in some cases if One airline buys an aircraft from Boeing but later sold it to other airlines then the code will not change

If the Ownership of the Aircraft was transferred before delivery of the aircraft, then the code will be changed to the current owner.

But after 2016 This code system is discounted by Boeing and replaced by Production Line No.

AIRBUS A350 BEST WIDE BODY AIRCRAFT