Horizontal and vertical writing in East Asian scripts

Chinese characters, Korean hangul, and Japanese kana may be oriented along either axis, as they consist mainly of disconnected logographic or syllabic units, each occupying a square block of space, thus allowing for flexibility for which direction texts can be written, be it horizontally from left-to-right, horizontally from right-to-left, vertically from top-to-bottom, and even vertically from bottom-to-top.

Since the nineteenth century, it has become increasingly common for these languages to be written horizontally, from left to right, with successive rows going from top to bottom, under the influence of European languages such as English, although vertical writing is still frequently used in Hong Kong, Japan, Korea, Macau, and Taiwan.

Chinese characters, Japanese kana, Vietnamese chữ Nôm and Korean hangul can be written horizontally or vertically.

Example in Japanese, with furigana in green: Bopomofo in Taiwan is usually written vertically regardless of the direction of the main text.

The former developed because the Uyghurs rotated their Sogdian-derived script, originally written right to left, 90 degrees counter-clockwise to emulate Chinese writing, but without changing the relative orientation of the letters.

'Phags-pa in turn was an adaptation of Tibetan script written vertically on the model of Mongolian to supplant those writing systems current in the Mongol Empire.

Its first issue in January 1915 explained the (then) unusual format: 本雜誌印法，旁行上左，並用西文句讀點之，以便插寫算術及物理化學諸程式，非故好新奇，讀者諒之。 This magazine is printed sideways from the top left, and marked with Western punctuation.

In publications, text is run horizontally although book titles on spines and some newspaper headlines remain vertical for convenience.

In Taiwan, Hong Kong, Macau, and among older overseas Chinese communities, horizontal writing has been gradually adopted since the 1990s.

This form was widely used for pre-WWII advertisements and official documents (like banknotes of the Japanese yen), but has not survived outside of old-fashioned signboards.

[3] Other major newspapers had already switched to horizontal writing by 1 January 1998; Dong-A Ilbo published its last vertical issue on 31 December 1997,[4] Kyunghyang Shinmun on 6 April 1997[5] (the day before its 50th anniversary), and Maeil Kyungje on 14 September 1996.

[6] Announcements about the impending change in these newspapers in the days preceding often shared a common theme of "appealing to younger audiences".

Some, however, such as Levius, are aimed at the international market and strive to optimize for translation and localization, therefore make use of horizontal text and speech bubbles.

Traditional characters are also used in mainland China in a few limited contexts, such as some books on ancient literature, or as an aesthetic choice for some signs on shops, temples, etc.

Some newspapers combine the two forms, using the vertical format for most articles but including some written horizontally, especially for headlines.

Scientific and mathematical texts are nearly always written horizontally, since in vertical writing equations must be turned sideways, making them more difficult to read.

This is not a fixed rule, however, and it is also common to see English words printed sideways in vertical writing texts.

In the standard language (표준어; 標準語) of South Korea, punctuation marks are used differently in horizontal and vertical writing.

Early computer installations were designed only to support left-to-right horizontal writing based on the Latin alphabet.

Today, most computer programs do not fully support the vertical writing system; however, most advanced word processing and publication software that target the East Asian region support the vertical writing system either fully or to a limited extent.

Additionally, OpenType also has valt, vert, vhal, vkna, vkrn, vpal, vrt2, vrtr "feature tags" to define glyphs that can be transformed or adjusted within vertical text; they can be enabled or disabled in CSS3 using font-feature-settings property.

Their latest efforts in 2011 show some revisions to the previous format for the Writing Mode property which provides for vertical layout and text display.

Among Web browsers, Internet Explorer was the first one that had been supporting vertical text and layout coded in HTML.

[13][14][15] Starting with Google Chrome version 48 in 2016, the unprefixed writing-mode property is now also supported by Chromium browsers, with the exception of the sideways-lr and sideways-rl values.