One of the most important documents in the third tranche of DoD UAP releases is this December 1948 Navy memorandum. The Fifth Naval District circulated instructions originating from the Chief of Naval Operations, who stated that the Director of Intelligence, U.S. Air Force, had informed the Navy that a "cycle of reappearance" of Flying Discs was apparent and that "the beginning of a new interval is imminent." Thank you so much for bringing to my attention @UnstblResearch