Didn't you know that some user asked here if their friends can give merit to each other eventhough the post wasn't that constructive and they got tagged by a DT member. Even you are unaware of it, use your common sense that it's really prohibited.
Just think of it if it's allowed, what is the purpose of merit system now? Your account is now proned to get tagged by a DT member. You can't reasoned that you are just asking because you are still newbie because generally, we don't know the status of the person behind every account.
Thank you for your suggestions. I will learn from experience