Just ended up needing this today. I use the impersonate feature to post category guidelines, or other pinned topics or replies in them under the @system account. What I currently do is post them under mine, then change ownership to @system, but what if someone has the topic set to watching, then they would see that it was me. I’m not necessarily trying to be anonymous when posting these, although, I just don’t want those posts under my name. I could make an alt whose purpose is to post these, although I would have to log in from a private window each time, which is bad ux.