Accessible output
Charts accept alt (up to 2000 characters), description (up to 4000), decorative, and dataTable: 'hidden' | 'none'. Alt text and long descriptions support Handlebars. Without authored alt text, the renderer generates an English summary of the resolved data; the selected locale formats values. Authors should explain the chart’s purpose and significant trend, beyond what an automatic summary can infer. Images accept decorative: true; their existing alt text remains available when the flag is cleared.
| Output | Supported semantics | Boundaries |
|---|---|---|
| HTML | SVG image role, accessible name, title and description; optional clipped chart-data table with caption and header scopes; decorative SVG/images excluded; scoped table/pivot headers | Hidden data remains available to HTML assistive technology. Verify reading order and meaningful descriptions with a screen reader. |
| Chromium tags, chart Figure alternate name, visible table/pivot Column/Row scopes; decorative images excluded; hidden signing anchors excluded from tags but extractable | Chromium omits clipped chart-data tables from PDF tags. The SVG long description is present in HTML; Chromium’s Figure alternate text uses the accessible name. Native page chrome, sticky content, links and post-processing have additional tag limitations. | |
| DOCX | Chart, image and barcode drawing descriptions; chart descriptions combine the name and long description | Decorative drawings omit alt metadata. The current writer does not emit Word’s native decorative flag. |
| PPTX | Image, chart and barcode descr metadata; chart descriptions combine the name and long description |
Omitting descriptions for decorative images does not set PowerPoint’s native decorative flag. Slide reading order requires manual review. |
| CSV/XLSX | Existing data export behavior | These chart/image accessibility fields do not create spreadsheet accessibility metadata. |
repeatHeader: false retains its existing behavior: the table header appears once. Header scopes are now explicit. Pivot row headings use th scope="row" with inherited font weight to preserve their appearance. Text/image watermarks and stamped TOC page numbers are marked as PDF artifacts; the existing font embedding remains in place.
Both buffered and streaming PDF paths request tagged: true. Hidden signing-anchor text remains in the searchable PDF text layer while carrying no marked-content ID. This is verified with PDF.js; test an actual signing integration before changing anchor text or fonts. Chromium excludes decorative images from the tag tree but leaves their paint unmarked rather than explicitly wrapping it in /Artifact. Repairing that content stream is part of the deferred PDF/UA work.
PDF/UA status
The engine does not claim PDF/UA conformance and exposes no pdf.pdfua option or identification checkbox. The required Chromium/veraPDF feasibility check failed all three fixtures after the proposed metadata pass. Content-stream marking and link alternate descriptions require further work; adding an identification flag would make a false conformance claim. See the Wave 47 spike.
Metadata language and title remain available through Document settings. Set the language of the document’s actual text, and supply a descriptive title. Automated tag tests and validators cannot establish meaningful alternatives, correct reading order, or complete human accessibility. Accessibility advice in the editor is advisory and does not block publication.
The new template fields are additive. Older strict readers may reject them; no database migration is required. Existing templates gain SVG names and explicit header scopes without changing chart geometry. Review authored descriptions and the final viewer output before distributing documents.