draft: pdf accessibility blog post

docs/blog/posts/2026-02-xx-pdf-accessibility-and-standards/index.qmd

@@ -0,0 +1,111 @@
+---
+title: PDF Accessibility and Standards
+description: |
+  Quarto 1.9 brings PDF accessibility and standards support, building on new tagging features in LaTeX and Typst.
+author: Gordon Woodhull
+date: "2026-02-xx"
+image: verapdf.jpg
+image-alt: "veraPDF logo"
+draft: true
+---
+
+2025 was a big year for PDF accessibility. LaTeX and Typst both released support for PDF tagging and accessibility standards, just in time for new regulations in the [EU](https://en.wikipedia.org/wiki/European_Accessibility_Act) (June 2025) and [US](https://accessible.org/ada-title-ii-web-accessibility/) (April 2026).  
+
+Quarto 1.9 brings this support to you as a Quarto user.
+
+## What PDF Standards Do
+
+Currently LaTeX supports the newer UA-2 standard, and Typst supports the older UA-1 standard. Typst is likely to have UA-2 support later in 2026.
+
+Both standards instruct the PDF renderer to provide screen readers:
+
+* The semantic structure of the text (title, heading, paragraph, figure, etc)
+* The natural reading order
+* Spatial coordinates for highlighting and assistive navigation
+* Required metadata such as title and language
+
+## How to enable a PDF Standard in Quarto
+
+In Quarto 1.9, specify a PDF standard for your document or project with `pdf-standard`
+
+::::: {layout-ncol=2}
+:::: {}
+**PDF (LaTeX)**
+
+```yaml
+format:
+  pdf:
+    pdf-standard: ua-2
+```
+::::
+
+:::: {}
+**Typst**
+
+```yaml
+format:
+  typst:
+    pdf-standard: ua-1
+```
+::::
+:::::
+
+`pdf-standard` takes a single standard name or list of standard names. PDF version is used if provided in the list, but otherwise inferred from the standard.
+
+If you specify a PDF standard, Quarto first instructs LaTeX or Typst to use the standard when producing the PDF, and then validates the output PDF against the standard using veraPDF, an open-source PDF validation tool. If veraPDF is not installed, you'll get a warning but still receive a PDF -- it just won't be validated.
+
+::: {.callout-note}
+## Installing veraPDF
+
+To install veraPDF, you'll first need Java, then run:
+
+```{.bash filename="Terminal"}
+quarto install verapdf
+```
+
+:::
+
+When a document passes validation, you'll see output like:
+
+```
+[verapdf]: Validating my-document.pdf against PDF/UA-2... PASSED
+```
+
+## Creating accessible PDFs
+
+Quarto's Markdown-based workflow handles many accessibility requirements automatically:
+
+* Document metadata (title, author, date, language) flows into the PDF's built-in metadata fields.
+* The semantic structure of Markdown satisfies PDF tagging requirements. For Typst this is always enabled; for LaTeX it is enabled when you specify a standard that requires it.
+* Alt text for images is carried through to the PDF for screen readers.
+
+But you do need to make sure your document has:
+
+* A **title** in the YAML front matter.
+* **Alt text for every image**, specified with `fig-alt`. See [Figures](/docs/authoring/figures.qmd#alt-text) for details.
+
+See the [LaTeX](https://prerelease.quarto.org/docs/output-formats/pdf-basics.html#accessibility-requirements) and [Typst](https://prerelease.quarto.org/docs/output-formats/typst.html#accessibility-requirements) documentation for more details.
+
+## Current limitations
+
+We ran our test suite -- 188 LaTeX examples and 317 Typst examples -- to find where Quarto PDFs do not yet pass UA-1 or UA-2, and where users will need to change their documents.
+
+### LaTeX
+
+Margin content is the biggest structural blocker. If you use `.column-margin` divs, `cap-location: margin`, `reference-location: margin`, or `citation-location: margin`, the resulting PDF will not pass UA-2. The underlying `sidenotes` and `marginnote` LaTeX packages [do not cooperate with PDF tagging](https://github.com/quarto-dev/quarto-cli/issues/14103). 
+
+(Margin content does work with Typst and passes UA-1 -- see [Typst Article Layout](/docs/output-formats/typst.qmd#article-layout).)
+
+There are smaller upstream issues in Pandoc, LaTeX, and LaTeX packages, [documented here](https://github.com/quarto-dev/quarto-cli/pull/14097#issuecomment-3947653207).
+
+### Typst
+
+In our tests, Typst catches every UA-1 violation, and fails to generate the PDF. veraPDF did not detect any violation that Typst did not.
+
+Typst also seems to do a very good job of generating UA-1 compliant output by default -- almost all errors were due to missing titles or missing alt text.
+
+However, we did discover that [Typst Books](/docs/books/book-output.qmd#typst-output) are not yet compliant. There is a [structural problem with the Typst orange-book package](https://github.com/flavio20002/typst-orange-template/issues/38) and we'll work with the maintainers to correct it.
+
+---
+
+We expect PDF accessibility support to improve upstream throughout 2026 as awareness of UA-2 and the new regulations spreads. If you run into accessibility issues with PDF output, please search the [Quarto discussions](https://github.com/orgs/quarto-dev/discussions) and open a new one with the `accessibility` label for any issues you discover.