Here in our country we have an option to split a land plot into smaller ones. If for some reason you cannot take neighbouring numbers, you get assigned letters.

Here in our country we have an option to split a land plot into smaller ones. If for some reason you cannot take neighbouring numbers, you get assigned letters. We have some land plots, which have been divided into many smaller ones. So, there are homes (or homes-to-be-built) with address "Street 10, Town" and "Street 1O, Town". I guess, postal service will make these people to get acquainted :)