I have just noticed that a few days after a question has been posted then the ability to post answers and add comments is disabled. I have no problem with that; however, what I do find surprising is the fact that any comments against answers disappear at the same time.
I frequently add clarification comments against specific answers when I believe there is some ambiguity in the answer. For example, if someone asks "How do I find my IP address?" and gets an answer "Run the command 'ipconfig /all'." I might add the comment "This applies to the IP on a Windows computer. The public IP address will be different if you connect through a router."
Now the comment disappears after a few days. Why?