PDFs should not have animations or scripts that make the screen flicker. This can cause seizures for users who have photosensitive epilepsy and can make the document much more difficult to interpret for users with low vision or cognitive disabilities. If there are animations or scripts that make the screen flicker in a document, remove the animations and scripts in order to pass this check.
WCAG requirement: 2.3.1 Three Flashes or Below Treshold
Typically, only advanced PDF authors will add scripts to a document. According to Adobe, if a document contains scripts, the content within the PDF cannot be script-dependent unless the content and functionality are still accessible with the use of the keyboard and assistive technologies. If scripting in a PDF interferes with keyboard navigation or prevents the use of assistive technologies, the document is not accessible.
If a document contains scripts, check them manually to ensure that they aren't compromising the document's accessibility.
WCAG requirements: 1.1.1 Non-text Content, 2.1.1 Keyboard, 2.2.2 Pause, Stop, Hide, 4.1.2 Name, Role, Value
Timed responses are found in PDFs that contain forms with JavaScript. Typically, only advanced users will add forms with JavaScript to a PDF.
A PDF with timed responses is not accessible. Remove timed responses so that all users have enough time to read the content and use or fill out the document.
WCAG requirement: 2.2.1 Timing Adjustable