My father is a rural mail carrier and can/has delivered letters addressed to

Grandma SmallTown, State, Zip

based on the return address. He has also seen his share of the 'white house south of the bank' addresses.

They now have real street addresses (I think for the county wide 911 system) but when I was younger our neighbor would use a multitude of vanity address. e.g.

Jane Smith 1 Dusty Lane Smalltown, State, Zip

or 123 Tumbleweed Rd or 555 Cow Pasture etc etc

UPS trucks usually knew where to deliver it based on the name or they would ask someone at the gas station where the person lived.