The `rel_canonical()` function in WordPress generates the `rel="canonical"` HTML attribute for pages with identical content, helping search engines identify the preferred version and avoid duplicate content issues
The `register_widget()` function in WordPress is used to register a custom widget with the platform by passing the name or instance of the widget class to the function
This article explains how to use the WordPress'register_uninstall_hook()' function to set an uninstallation hook for a plugin, which can perform specific actions during the uninstallation process