The identifier should be a GUID with an option for tagging and comments for developers and translators. Other languages depend on other contexts which are not represented here, like multiple forms of "present" tense, or the current time of day. Keying translations on English-language concepts is a bad idea, as a lot of languages are unlike English. Treating English as one of the translations (and not the reference) is a good idea that will prevent problems with future translations and avoid re-architecting your whole localization pipeline (and code base).
