In Part 2 you gained more insight into using the gettext library by learning the most important functions of the extension. In this part you’ll learn how to best use a fallback locale, switch between locales, and override the currently selected message domain. So without further ado, let’s dive in! Directory Structure and Fallback Locales If you’ve been following along in the previous articles, you should have the following directory structure for testing the gettext library. While it is typical, it is not designed to achieve the best performance.