Abbreviations dictionary abbreviations, acronyms, contractions, initials and nicknames, short forms and slang short-cuts, sign and symbols, including astronomical constellations, stars, and symbols; automatic data-processing abbreviations for zip-coded mail; chemical element symbols, atomic numbers, discovery data; civil and military time systems compared; diacritical and punctuation marks; Greek alphabet; international civil aircraft markings; international radio alphabet and code; numbered abbreviations; proofreader's marks; Roman numerals; ship's bell time signals; signs and symbols frequently used; weather symbols