A memorandum was a type of report.
In 2374, a PADD containing a draft of a secret memorandum addressed to Gul Dukat was "lost" by its writer, Damar. In it, he suggested the poisoning the last remaining ration of ketracel-white in order to eliminate Jem'Hadar suffering from withdrawal due to its shortage. In reality, Rom had stolen it and made sure the Jem'Hadar found it. This lead to a fight which left three Cardassians dead and several patrons of Quark's injured. Later, Weyoun berated Damar in Dukat's presence, asking how the Cardassian could "have been so stupid as to leave such an inflammatory document lying around for anyone to find?" (DS9: "Behind the Lines")