In the last five years, I provided technical support to the customers of Hreflang Manager. A plugin for WordPress that allows to specify the alternative versions of a page for different languages or regions with hreflang.
In general, the support questions for a WordPress plugin are strictly related to the plugin itself, but in this case, most of the questions were related to the general concepts associated with hreflang.
In this article, you can find the most common questions I had to answer.