Non-Mongolian characters in vertical Mongolian text

[r12a]

Fullwidth Latin alphabetic and digit characters are seen in traditional Mongolian text, as are fullwidth Chinese characters and punctuation (see w3c/type-samples#38). When used, they are displayed upright. The fullwidth series of Unicode characters may be used as an easy way to achieve this. Cyrillic characters may also be seen used in a way that resembles fullwidth characters, but this is actually a property of the font used to display the characters, since there are no fullwidth cyrillic code points in Unicode. Emoji are also expected to be displayed upright.

Non-fullwidth letters and numbers tend to be written sideways. See w3c/type-samples#26.

Upright digits are used for list counters. A common approach involves the use of circled digits being used for list counters w3c/type-samples#28. However, counters may also run down the page (see w3c/type-samples#37).

Mongolian also has the feature referred to in Japanese as tate chu yoko, whereby small sequences of non-fullwidth numbers or punctuation may run horizontally within the vertical flow.

Question marks and exclamation marks are often (always?) fullwidth, upright characters. See an example at w3c/type-samples#27.

Parentheses, brackets and quotation marks (double angle bracket) are often also fullwidth, but punctuation such as 「」、【】、（）、…、－、＝ etc. is rotated as in Chinese. See the previous example. Sometimes, however, these are not fullwidth (though they are still rotated). See xxx. Both ASCII "()" and fullwidth "（）" parenthesis characters can be found, and both "«»" and “《》”.

Many of the conventions seen in actual digital text may be determined more by the available technology than by what the content author wants to achieve.

Thanks to: Jirimutu, SiqinBilge, Badral Sanlig, and 梁海 Liang Hai for this information.

[xfq]

We should add this to the mlreq document, maybe to the Punctuation section and the Vertical text section.