CSS: “text-justify”: “inter-ideograph” is not a “text-justify” value.

The value inter-ideograph is not part of the CSS text-justify specification and will not pass validation.

The text-justify property controls how the browser distributes spacing when text-align is set to justify. The value inter-ideograph was an Internet Explorer proprietary extension that added extra spacing between ideographic (CJK) characters and words. It was never standardized by the W3C and is not recognized by modern browsers.

The valid values for text-justify in the current CSS Text Module Level 3 specification are:

• auto — the browser chooses the best justification method based on the content language. For CJK text, most browsers already apply inter-ideograph-style spacing automatically with this value.
• inter-word — spacing is distributed between words only (best for Latin scripts).
• inter-character — spacing is distributed between characters (useful for CJK text).
• none — disables justification.

For content that mixes CJK and Latin text, auto is usually the best choice, since the browser will apply appropriate spacing rules for each script.

HTML examples

Before (invalid)

<p style="text-align: justify; text-justify: inter-ideograph;">
  This text uses a non-standard value.
</p>

After (valid)

<p style="text-align: justify; text-justify: auto;">
  This text uses a valid value. The browser applies
  appropriate justification based on the content language.
</p>

Learn more:

MDN Reference

CSS text-justify - MDN Web Docs

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