memorandum

announcement, bulletin, declaration, notification, posting, proclamation, pronouncement, release

dispatch, report

edict, pronunciamento, rescript

charge, command, dictate

directions, instructions, orders, word

encyclical, epistle, jotting, letter, mail, message, missive, note, post [chiefly British]

billet-doux, open letter

airmail, card, electronic mail, e-mail, junk mail, mail, postal card, postcard

communication, report

encyclical

bordereau, memoir, memorial, minutes, protocol, report

line

document, writing