A "short memo" refers to a brief written document that provides important information or instructions. It is a concise way to convey specific details to others without going into lengthy explanations. Full definition
All they can offer is nostalgia for simpler days, some deprecatory remarks about our 24 - hour news cycle, and a forlorn endorsement of shorter memos for the President (the demand for which was, as I recall, widely regarded by critics as a symptom of intellectual vacuity in the Reagan Adminstration). (firstthings.com)
But ARS jumped the gun on the release of Young's memo, Bentley says, and the terse wording in Drumm's short memo generated a firestorm. (sciencemag.org)
Strong ability to communicate in standard English language; read and understand short memos and correspondence, and simple instructions; and to write simple correspondence (jobdescriptionandresumeexamples.com)