title: Address field validation for iOS / Mac
body: <p>I want to create an "Add Address" view, a very basic "Street, City, Zip, Country" type of page: multiple text fields inside a table view. This is simple if you only ever added U.S addresses, but I'm not sure about how to do this the right way though, handling all international use-cases as well. Essentially:
  1. How do you pick the right field label for each country? For e.g. for US / Australian addresses, the field should be called "State"; for UK, it's called "County", in some places it's called "Province". How do you know what the label should say (short of hard-coding logic myself for each country)?
  2. How do you validate the values for those field? UK postal codes have a certain format, whereas in the US it's a 5-digit ZIP code. Also, in the US, there is a list of states that the user can select. How do you get that list?</p>
  
  <p>I've looked into NSLocale, and can't find any way to do this. Surely there must be a good and easy way to do this?</p>