Don't even try to do validation on postal addresses. The postal system has so many corner cases that you'll never be able to correctly handle all of them. Every

Don't even try to do validation on postal addresses. The postal system has so many corner cases that you'll never be able to correctly handle all of them. Every mishandled corner case will cost you, or your counter-party, time and money. Just dump addresses into a unicode string and let the postal system figure it out.