Warichū
Warichū (割注 or 割註, sometimes 割り注, literally "split annotation") is the Japanese word for the traditional East Asian typographic device of typesetting in small double lines editorial comments, notes, parenthetical comments, and other annotations that may or may not belong to the text proper. It is used for the same kind of text which in English would be placed between parentheses or brackets, or in footnotes. The word "warichū" itself is used in some computer programs that deal with "CJK" typesetting, and in discussions about CJK typography. Visual appearance. The "warichū" is typeset by setting the annotation using small  type that is about half size, cutting it into two equal parts, stacking them on top of each other, and then putting the resulting stacked lines into the space of a normal line of text. Because Han characters are typically typeset with equal width and height, the two halves of a warichū annotation should contain exactly the same number of characters if the annotation itself contains an even number of characters. If the annotation contains an odd number of characters, the first half should have exactly one character more than the second half. If the annotation is too long, line  wrapping may occur. In that case, the warichū itself will behave like two or more tiny pages, wrapping the annotation inside several parts of the line-wrapped warichū. Modern use. In Japanese typography, warichū is still sometimes used, in dictionaries for example. However, it has fallen into disuse in Chinese typography to such an extent that Chinese people will most likely either find it archaic, or will not know what it is when they see it. Warichū tend to be used only in vertical writing. Warichū in computing. Some of the typesetting programs and word processors support typesetting warichū if  support for "Asian" typography is turned on. In Adobe Illustrator and Adobe InDesign, it is called "warichu"; some other programs (for example, OpenOffice.org) avoid the word by calling it "writing in double lines", describing the visual appearance of warichū. Some programs claim to support warichū but fail to do it correctly. For example, some programs cannot split the annotation into "equal" halves. Adobe Illustrator allows one to create warichū which consists of more than two lines, though warichū is traditionally always split into only two lines. Warichu is also a social annotation tool for Internet Explorer and Firefox/Mozilla  derivative browsers. There is also a macro for typesetting warichū in LaTeX, called Gezhu ().