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EPUBCheck · Accessibility

ACC-009

Updated:

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.

The official message

MathML should either have an "alttext" attribute or "annotation-xml" child element.

Default severity
Usage. Informative only and hidden by default: it appears when EPUBCheck runs with -u (--usage). It does not make the EPUB invalid.
EPUBCheck version
5.4.0

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.

Terms used here

Other ACC messages

  • ACC-011 SVG hyperlink has no accessible name

Message text and severity from EPUBCheck 5.4.0 (W3C, BSD-3-Clause). Explanation by EPUBLab.

FAQ

What does EPUBCheck ACC-009 mean?

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.

Is ACC-009 an error?

ACC-009 is reported as usage by default. Informative only and hidden by default: it appears when EPUBCheck runs with -u (--usage). It does not make the EPUB invalid.