Thanks again for your reply, AoP. I'm not sure if your explanation is a logical guess or if you are answering knowledgeably with an official answer. The reason I'm still questioning your answer is because that explanation seems to fit why the display "action unknown" would appear better than why the "nothing, or nothing you can see, anyway" display would appear.
I hope you will forgive my persistence, but I'd really like to know the difference between "action unknown" and "nothing, or nothing you can see, anyway," then.
Do you think the "nothing, or nothing you can see anyway" appears when someone might click on read latest post of this member from their profile?
I'm pretty familiar with this type of forum, so I understand pretty well all the buttons, features, functions, etc. I just have not been able to figure out why those two displays sometimes appear on the "who's online" page.
Although, I do know that "unknown action" appears when someone is either deleting comments or deleting an account. I wonder if it might appear when someone is modifying a comment.
Do you or anyone else have more precise answers to my questions?