# EPUBCheck ACC-009: MathML should either have an alttext…

Source: https://epublab.com/epubcheck/acc-009/ (updated 2026-11-03)

EPUBCheck ACC-009 is a usage message: “MathML should either have an "alttext" attribute or "annotation-xml" child element.” A MathML equation has no text alternative: neither an alttext attribute nor an annotation-xml element.

- Official message (EPUBCheck 5.4.0): MathML should either have an "alttext" attribute or "annotation-xml" child element.
- Default severity: Usage

## Typical causes

- Equations converted to MathML without a text description for screen readers.

## How to fix it

- Add alttext to the math element with a readable form of the equation.

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EPUBLab.