Filters are for where you return a possibly modified first argument. If you just want to trigger an event and don’t want a return value, use do_action instead Creating your own filter call There must be at least 1 argument passed (the first argument is intended to be the value that is to be filtered […]

Creating your own action call The function other plugins and theme can add if they want to receive your special action call The call you do that will trigger anywhere my_action_name has been added

Handling filter calls from WordPress and plugins