What is another word for "circular"?

Roget's Thesaurus (1911) lists these synonyms for "circular": account, accredit, billet, billet-doux, bulletin, capital, card, chit, chitty, correspond, correspondence, creance, credit, creditor, debenture, despatch, dispatch, draft, dun, duplicate, epistle, epistolary, favor, floating, fly, give, intrust, keep, kite, lender, lessor, letter, lien, line, messenger, missive, mortgage, mortgagee, note, open.