How to Add Sponsored Post Prefix to Post Title in WordPress
Igor Benić on Twitter: "- if functions are registered through a class, they won't be removed by just putting the function name. add_action( 'init', [ $object, 'the_function' ] ); remove_action( 'init', 'the_function');
Wordpress Hooks Tutorial for beginners from scratch #16 Filter hook "the_content" - YouTube