MessageKey

MessageKey = "label" | "hint" | "empty" | "bad_character" | "bad_length" | "unknown_state" | "bad_lga" | "bad_area" | "bad_unit" | "suggestion" | "use_suggestion" | "legacy_accepted" | "legacy_rejected" | "valid" | "checking" | "not_found" | "confirmed" | "confirmed_place" | "check_failed" | "secret_key" | "use_location" | "locating" | "gps_coarse" | "gps_not_found" | "gps_denied" | "gps_unavailable"

The key of each message that the field shows. spec/field.md says when each one shows.