We have lots of code where we manipulate strings like "en", "en_US", "en_US.UTF-8". As you may guess, manipulating language identifiers as strings is error prone and inconsistent. I've created a little class, LanguageTag, to encapsulate the handling. https://www.rubydoc.info/github/yast/yast-packager/master/LanguageTag I am quite sure that you will find it lacking, because I thought YAGNI[3] and only implemented what I strictly needded for my fix[1]. Please let me know if you see a place where this would be useful, let's use it and improve it. For reference, https://en.wikipedia.org/wiki/IETF_language_tag or http://www.langtag.net/ is the standard that I was following, before scrapping it as too complex for my usecase[2]. Still, we should use matching concepts and not reinvent wheels. [1]: https://github.com/yast/yast-packager/search?q=LanguageTag&unscoped_q=LanguageTag [2]: https://github.com/yast/yast-packager/pull/441 [3]: https://en.wikipedia.org/wiki/You_aren't_gonna_need_it -- Martin Vidner, YaST Team http://en.opensuse.org/User:Mvidner