Punctuation 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. By the 19th century, punctuation in the western world had evolved "to classify
Chinese punctuation from "halfwidth" European punctuation marks. Chinese characters can be written horizontally or vertically. Some punctuation marks adapt to this change in direction: the parentheses, square brackets, square quotation marks, book title marks, ellipsis marks, and dashes all rotate 90° clockwise when used in vertical text. The three underline-like punctuation marks in Chinese (proper noun mark, wavy book title mark, and emphasis mark) rotate and shift to the left side of the text in vertical script (shifting to the right side of the text is also possible, but this is outmoded and can clash with the placement of other punctuation marks).