If you use this library, and want to be notified about important changes, please sign up to our mailing list. NOTE: A lot of methods in this class require Region Code strings. These must be provided using ISO 3166-1 two-letter country-code format. These should be in upper-case. The list of the codes can be found here: http://www.iso.org/iso/country_codes/iso_3166_code_lists/country_names_and_code_elements.htm