... or there's a software engineer somewhere who simply assumed that three letter navaid identifiers were globally unique, and baked that assumption into the code.
I guess we now need a "Falsehoods Programmers Believe About Aviation Data" site :)
And this is why you always use surrogate keys and not natural keys. No matter how much you convince yourself that your natural key is unique and will never change, if a human created the value then a human can change the value or create duplicates, and eventually will.
I guess we now need a "Falsehoods Programmers Believe About Aviation Data" site :)