Overleaf project: pdfua2-mathml-af-se-alt (read-only)
This file tests AF + SE + Alt text: all three encoding methods are active simultaneously. MathML is embedded as an Associated File, written into the PDF tag tree as Structure Elements, and a plain-text alternative is auto-generated on the formula tag. This is the most complete encoding combination tested.
| File | Description |
|---|---|
main.tex |
LaTeX source |
pdfua2-mathml-af-se-alt.pdf |
Compiled PDF output |
latexmkrc |
Overleaf compilation configuration (shared across all six projects) |
\DocumentMetadata configuration\DocumentMetadata{
lang=en,
tagging=on,
pdfstandard = {ua-2, A-4f},
tagging-setup={
math/setup = {mathml-AF, mathml-SE},
math/alt/use = true
}
}
Key choices:
pdfstandard = {ua-2, A-4f} — A-4f is required here because the AF method embeds MathML as a file attachment on each formula object. See the top-level README.math/setup = {mathml-AF, mathml-SE} — Both AF and SE MathML encoding are active simultaneously.math/alt/use = true — Auto-generates a plain-text Alt attribute on the formula tag in addition to both MathML delivery channels.lang=en — See the top-level README for the reasoning behind using en rather than en-US.| Screen reader + PDF viewer | Result |
|---|---|
| NVDA with Adobe Acrobat Pro | ❌ Alt text (static string; no interactivity) |
| JAWS with Adobe Acrobat Pro | ❌ Alt text (static string; no interactivity) |
| NVDA with Firefox | ✅ Configurable math speech/braille; interactive expression exploring |
| JAWS with Firefox | ✅ Configurable math speech/braille; interactive expression exploring |
| NVDA or JAWS with Chrome/Edge | ❌ Math is skipped over; not read aloud |
| VoiceOver macOS (all viewers) | ❌ Speaks as gibberish / math skipped |
See the full results table for complete detail and test dates.
Despite containing the richest encoding — AF, SE, and Alt text all present — this combination produces the same results as AF+Alt and SE+Alt in every tested environment. The Alt attribute suppresses MathML access in Acrobat regardless of how many MathML delivery channels are also present. Firefox continues to correctly route to MathML via MathCAT regardless of the Alt attribute.
The key finding from this combination is that adding Alt text does not provide a safety net for environments where MathML fails — it actively degrades the experience in environments where MathML would otherwise succeed (Acrobat with NVDA). The decision to include math/alt/use = true should therefore be made carefully, with an understanding that it trades MathML access in Acrobat for a static text fallback.