So airport codes are no better than "standard" book numbers - ISBNs are not unique, contrary to what one may thing, and, yes, the mantra is "one book, two numbers" because there is "old" ISBN and the more recent "ISBN-13" with more digits.
I started cataloging my home library using the barcodes on the books and pulling the meta-data from Amazon via ISBNs, but ever so often, the cover image pulled was for a completely different book, although the barcode contains a check sum and the Amazon data was not incorrect. The reason? ISBN re-use! (rolling eyes)
This reminded me of the dude in one former company who proposed to reuse UUIDs...
So airport codes are no better than "standard" book numbers - ISBNs are not unique, contrary to what one may thing, and, yes, the mantra is "one book, two numbers" because there is "old" ISBN and the more recent "ISBN-13" with more digits.
I started cataloging my home library using the barcodes on the books and pulling the meta-data from Amazon via ISBNs, but ever so often, the cover image pulled was for a completely different book, although the barcode contains a check sum and the Amazon data was not incorrect. The reason? ISBN re-use! (rolling eyes)
This reminded me of the dude in one former company who proposed to reuse UUIDs...