This issue is applicable to Chinese, Japanese, Korean, and Mongolian.

By default, in runs of Latin alphanumeric text the letters are rotated 90º and run down the page. However, in some instances the alphanumerics need to stand upright. For example, this is important for acronyms.

Browsers need to allow content authors to indicate where alphanumerics should be rendered upright.

The GAP

writing-modes The CSS text-orientation property has a value upright which is meant to produce this behaviour, but not all browsers support it.

Priority

Upright-oriented Latin text, especially, is used commonly for acronyms in Chinese, Japanese, Korean, & Mongolian vertical text, so this is a significant gap for general web content.

Tests & results

Interactive test, text-orientation:upright will make Latin characters and digits sit upright in vertical text.

Action taken

Webkit

Outcomes

All major browser engines now support this feature!