That's a bit curious though. If the code relies on a magic value, you'd think it's in order to skip trying to get data it doesn't have, like the address of the unidentifiable cars.
Even if NULL then does have this address attached, why does it take the branch where it looks for the data?
I suppose it would be in a relational DB, perhaps there's a join that drops missing entries, but if they aren't missing they show up?
The code doesn't rely on a magic value, the humans have decided that an empty value will be typed, by hand, into their terminals as the characters "NULL".
The problem is that the employees with access to the system are required to enter a 'valid' value. But in some cases there is no value. So the 'valid' value they've come up with is the string "NULL" - they can't use "~~NULL~~" because ~ isn't allowed on a license plate. So because A) anyone can request a valid value on a plate, and B) nonce values must also be "valid" within the system, the tax payer is capable of ordering a nonce value on a plate.
They're likely different organizations. The one that entered 'NULL' license plates was a "privately operated citation processing center" so they presumably weren't in charge of looking up the addresses for each license plate. If they were it would be rather pointless to save the 'NULL' value in the first place.
Even if NULL then does have this address attached, why does it take the branch where it looks for the data?
I suppose it would be in a relational DB, perhaps there's a join that drops missing entries, but if they aren't missing they show up?