They probably had formal addresses but used informal directions. They do this in my grandmother's small town. No one will give you an actual address despite having one.

Concur, from reading the article I got that formal system was officially instituted and put in the books, but nobody used it. Trying to verify this by Googling only brought existence of formal addresses to light... which is what author was suggesting.

Fascinating aspect of this is dominance of structured, but ultimately useless* information on the internet. * - as claimed by the author, as noted above I was not able to get a clear picture after ~5 minutes of Googling.