[todo] Create an issue on csswg-drafts requesting a unit representing the width of IDEOGRAPHIC SPACE U+3000 of the font

[kidayasuo]

This is outcome from the F2F meeting on 2024-4-17.

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9.1. First Line Indentation: the ‘text-indent’ property

In Japanese text, the style of indenting the first character of a paragraph is typically achieved by inserting a full-width space. To achieve this indentation using the 'text-indent' property without inserting characters, it is necessary to define a unit that accounts for the width of the full-width space character of the font. Although the ic unit, which represents the width of Kanji, is currently defined, it is not uncommon for the widths of Kanji and full-width space characters to differ in fonts. One example is the default MS P Gothic on Windows, and another is AXIS Condensed / Compressed. In the latter, Kanji and Kana are monospaced, yet Kana is set narrower than Kanji, and both full-width spaces and punctuation have the same width as Kana.

Below is feedback from the Type Project:

"In AXIS Font Condensed, as you mentioned, full-width spaces and punctuation are based on the Kana width. Therefore, it is understood that a typesetting system based on Kana is being used. In other words, a text composed solely of Kana and punctuation would serve as the typesetting standard for AXIS Font Condensed.
Just as proportional Western text intervenes as an exceptional element in the normal setting of square-bodied Kana and Kanji, in AXIS Font Condensed, it is simpler to think of the typesetting system as being based on Kana width, involving Kanji and proportional Western text.
In fact, when writing texts like this, it feels natural to intermittently insert Kanji into a flow primarily composed of Kana.
Based on this, the appropriate amount of first-line indentation in AXIS Font Condensed would be the width of a full-width space (760/1000)."

As a result of the discussion, it was concluded that a definition of a unit representing the width of a full-width space character is needed.

Actions

Mr. Kida will create an issue on csswg-drafts.

[kidayasuo]

Update on the progress: As the name of this unit, we initially thought that we will change the definition of 全角, or create a new term 全角幅. At the JLReq TF meeting on 2024-7-9, an issue raised that changing the meaning of 全角, or using similar term 全角幅 could be confusing. The discussion is ongoing on its email list. Will update once we reach an agreement.

Note, the English term fullwidth is not a direct translation of全角. The fullwidth is defined as the advance width of monospaced CJK glyphs, whereas 全角 assumes that the shape of the glyph body is square and it is sometimes means the square, and sometimes it means the dimension of it.