What makes Blocking Mode even better than Call Barring is that it allow you to have an allowed list that will not be blocked from contacting you. Just tap and hold the number or contact and a small menu will pop up, then select Add to reject list. You have several options to block incoming calls.
Type a phone number, or tap to pick a contact or a recent caller to block. Why do you need to use this feature. The wikiHow Tech Team also followed the article's instructions and validated that they work.