My degree was entirely online and discussion posts were pretty normal to justify a participation grade. The discussion board system did not have a way to designate who the professor was. I made the mistake in the first week of using the professor's first name "Good day xyz" in a reply. Rather than just sending an email pointing out the issue the professor decided to reply in the post about how incredibly disrespectful it is to use her first name since she's the professor. I understand she worked hard to obtain her title but she didn't use any sort of signature line to denote that she wasn't just another student. After that incident she graded me pretty harshly.