Other elements alternate text – Failed

Other elements alternate text – Failed is a result from the Accessibility Checker in Adobe Acrobat Pro, in its Alternate Text category. It covers content other than figures that needs a text alternative. Adobe's help gives multimedia, annotations and 3D models as examples. Formulas belong to the same family: PDF/UA, the ISO standard for accessible PDFs, requires alt text on every Formula tag, the structure tag for an equation, and Includoc reports missing formula descriptions under this Acrobat rule.

What this means

Some content can't be read aloud as it stands:

• Formulas. Math is drawn with special symbols, characters placed above and below each other, and lines. A screen reader can't make sense of it, so the Formula tag needs alt text that says the expression in words.
• Multimedia and 3D models. These need a description of what they show. Captions and transcripts are separate requirements that have to come from the media itself.
• Annotations. Comments, stamps and attachments need descriptions. See Annotation has alt text.

If the failed items aren't any of these, look for small graphics tagged as content, such as rules, borders or underlines, that should have been marked as decoration (artifacts) instead.

How to write alt text for a formula

Say it the way a teacher would read it aloud. For the quadratic formula, that's: "x equals negative b, plus or minus the square root of b squared minus 4 a c, all over 2 a." A few habits help:

• Keep variable names exactly as written.
• Use grouping words, such as "the quantity" or "all over", to show what belongs together.
• Read fractions, powers and roots in a consistent way across the document.
• For a long derivation, describe each line as its own formula rather than writing one huge description.

Why it matters

People who can't see the page, and who use a screen reader or braille display, can't access what an undescribed formula says. In course materials, reports with statistics or engineering documents, a missing formula can mean a missing step in an argument. This is WCAG 2.1 success criterion 1.1.1, Non-text Content.

How to fix it in Acrobat Pro

Fix it in the source file

• Word: Microsoft documents that recent versions of Word export equations as Formula tags with an alt text entry and a MathML copy of the math. Older versions don't, and their equations can arrive as loose symbols. Update Word if you can, and check that each exported formula's alt text reads the equation correctly.
• Other tools: many tools export equations as a mix of symbols and lines with no description. Plan to add descriptions after export, or ask whether readers would be better served by also offering the source file.
• Media: add captions and transcripts to the video or audio itself before it goes into the PDF. A PDF can't add them later.

Fix it automatically with Includoc

Our AI drafts a spoken version of each formula, using the rendered equation and the text around it. You must check each one on the review screen. Math is easy to get subtly wrong, and a wrong formula description can mislead more than a missing one. For heavy math or science documents, the human-verified tier is the safer choice.

Embedded audio and video are flagged rather than fixed: we can't create captions or transcripts, because they have to come from the media itself.

Standards

Related errors

• Figures alternate text – Failed: the same requirement for images.
• Annotation has alt text: descriptions for comments, stamps and attachments.

For more on writing descriptions, read How to write alt text, or check a PDF free to find formulas and other elements without descriptions.