So when I was working for a web dev shop, one of the clients asked us to have a drop down of all the different combinations you can have for street types to appear on the address form of their shopping cart. So stuff like "Street", "St", "Drive", "Dr", "Lane", "Ln" etc. We told the client that it wasn't possible since the possible combinations and how some street don't all end with a type.

But the client was adamant about having this so we ended up building a section in the administration section to allow the client to add any new street type to a database table that will populate the dropdown.