You are correct with the whole valid words. Hopefully it is documented per country on what the valid types of thoroughfares are. I can't do a check against the central government registers because the majority of the world's governments don't let their postal files out of the country. Some because they don't want to, others because they have no idea where everyone lives. What is the difference between Mailbox and Box (which is what I have that a PO Box is called in Sweden) is this right?