<P> In the late 8th century a different system emerged in France under the Carolingian dynasty . Originally indicating how the voice should be modulated when chanting the liturgy, the positurae migrated into any text meant to be read aloud, and then to all manuscripts . Positurae first reached England in the late 10th century probably during the Benedictine reform movement, but was not adopted until after the Norman conquest . The original positurae were the punctus, punctus elevatus, punctus versus, and punctus interrogativus, but a fifth symbol, the punctus flexus, was added in the 10th century to indicate a pause of a value between the punctus and punctus elevatus . In the late 11th / early 12th century the punctus versus disappeared and was taken over by the simple punctus (now with two distinct values). </P> <P> The late Middle Ages saw the addition of the virgula suspensiva (slash or slash with a midpoint dot) which was often used in conjunction with the punctus for different types of pauses . Direct quotations were marked with marginal diples, as in Antiquity, but from at least the 12th century scribes also began entering diples (sometimes double) within the column of text . </P> <P> The amount of printed material and its readership began to increase after the invention of moveable type in Europe in the 1450s . As explained by writer and editor Lynne Truss, "The rise of printing in the 14th and 15th centuries meant that a standard system of punctuation was urgently required ." The introduction of a standard system of punctuation has also been attributed to the Venetian printers Aldus Manutius and his grandson . They have been credited with popularizing the practice of ending sentences with the colon or full stop, inventing the semicolon, making occasional use of parentheses and creating the modern comma by lowering the virgule . By 1566, Aldus Manutius the Younger was able to state that the main object of punctuation was the clarification of syntax . </P> <P> By the 19th century, punctuation in the western world had evolved "to classify the marks hierarchically, in terms of weight". Cecil Hartley's poem identifies their relative values: </P>

Who is credited for introducing a standardized system of punctuation
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