Zipcode patterns are documented as generated from http://i18napis.appspot.com, which does not work anymore. I assume that this is similar to the data available at https://chromium-i18n.appspot.com/ssl-address for the libaddressinput of google.

When looking at the Java library for libaddressinput which consumes this data, the zipcode is matched case insensitively: https://github.com/google/libaddressinput/blob/2610f7b1043d6784ada41392fc9392d1ea09ea07/common/src/main/java/com/google/i18n/addressinput/common/FieldVerifier.java#L156-L163

This library performs case sensitive matching in

Would it make sense to update the implementation to match the behavior of libaddressinput ?