Rules of the Road: BOTH INTERNATIONAL & INLAND An anchored vessel is servicing an aid to navigation...

Are you serious. Of course it can

and not only is a RAM, but its also working, so Sounds reqd in restricted visibility are NOT for at anchor

27 (b) A vessel restricted in her ability to maneuver, except a vessel engaged in mine clearance operations, shall exhibit… at anchor, in addition to the lights or shapes prescribed in paragraphs (b)(i) and (ii) (RWR), the light, lights or shapes prescribed in Rule 30 (anchor lights)