The design of a Unicode font
Charles Bigelow, Kris Holmes · 1993
this paper we often use the term character rather more loosely, and more in keeping with tradition and ordinary language, to mean an element of a script or a unit of a writing system. By script or writing system we mean a graphical representation of language. Hence, a character in this looser sense is any significant unit of writing, e.g. a letter of the Latin alphabet, an ideograph (more properly, logograph) of the Chinese writing system, a numeral, a punctuation mark, a symbol, a unit of space. Prior to the invention of typography, characters were rendered `on-the-fly' by the hand of a writer and the kind of logical distinction that Unicode draws between character and glyph was not as sharply defined. Handwriting usually contains context-sensitive variations, and in any writing system, some rules of variation are explicitly formalized, while others are unconscious. Accumulated contextual glyphicvariations are what transformed capitals into lowercase, for example, and turned roman into italic. The invention of typography resulted in unvarying, prefabricated, mass-produced glyphs in the form of printing types. The separation of text composition from letterform creation, and the need for bureaucratic indexing, storage, and retrieval of typographic characters, encouraged a conceptual distinction between the abstract notion of a character or letter and the tangible realization of it as a piece of type. Because the preponderance of characters composed, displayed, and printed by computer are typographic, the implicit disjunction between abstract character and concrete glyph has achieved a logical formulation in the Unicode standard.