Tag PDF links so they are announced
A working, announced link in a PDF is three things joined together. A Link tag in the structure tree, a link object reference pointing at the clickable annotation, and the text objects that give the link its words. W3C publishes PDF11 as a sufficient technique when the link text itself makes the destination clear, so the tagging and the wording are one job rather than two. Authoring tools build all three when you export a tagged PDF with real hyperlinks. Links drawn on afterwards in an editor usually end up as a bare annotation with nothing in the tree. One trap worth knowing. The tooltip Acrobat's Link dialog offers you is not exposed to screen readers, so it cannot rescue link text that says nothing.
How we find it in an audit
We pull up the screen reader's links list and compare it with the links visible on the page, because missing or nameless entries mean broken tagging. Then we tab to each link, check it announces its text, and press Enter to confirm it actually goes somewhere. Following the link is part of the test, not a bonus. In Acrobat's Tags panel we inspect the Link elements and the object references inside them.
How affected users experience it
An untagged link either never appears in the links list, so the user cannot find the dispute link everyone else clicks, or it is announced bare as "link" with no text. Either way, the path the document depends on is invisible or nameless.
Passes vs. fails
Passes
The exported statement tags each link properly. The Link element wraps the annotation and the text "Dispute a transaction online", it reads from the links list, and Enter opens the page.
Fails
A credit card statement's "dispute a transaction" link is an annotation drawn over flat text, with no Link tag. Screen readers list zero links in the document.
How this gets tested
The W3C publishes test rules that define what a checker looks for here.
- ARIA attribute is defined in WAI-ARIAA tool can check this
- ARIA state or property has valid valueA tool can check this
- Element with role attribute has required states and propertiesA tool can check this
- Form field has non-empty accessible nameA tool can check this
- Headers attribute specified on a cell refers to cells in the same table elementA tool can check this
- Role attribute has valid valueA tool can check this
- ARIA global properties not used where prohibitedA tool can check this
- ARIA required context roleA tool can check this
- ARIA required owned elementsA tool can check this
- ARIA state or property is permittedA tool can check this
- Table header cell has assigned cellsA tool can check this
- Iframe with interactive elements is not excluded from tab-orderA tool can check this
- Scrollable content can be reached with sequential focus navigationA tool can check this
- Link has non-empty accessible nameA tool can check this
- Link in context is descriptiveA tool can check this
- Links with identical accessible names and same context serve equivalent purposeA tool finds candidates, you decide
- Link is descriptiveA tool can check this
- Links with identical accessible names have equivalent purposeA tool can check this
Other ways to satisfy this rule
52 guides on this site are filed under 1.3.1 Info and Relationships. W3C lists this one as sufficient for that rule when used for making information and relationships conveyed through presentation programmatically determinable, so the condition is part of the test rather than a footnote to it.
- ARIA11sufficientAdd landmarks so users can skip around
- ARIA12sufficientUse role=heading when h1-h6 is impossible
- ARIA13sufficientName repeated landmarks so they are distinguishable
- ARIA16sufficientName controls from visible text with aria-labelledby
- ARIA17sufficientGroup related form fields with ARIA roles
- ARIA20sufficientMark leftover page areas with role=region
This guide is our interpretation of W3C technique PDF11: Providing links and link text using the Link annotation and the /Link structure element in PDF documents. W3C publishes its techniques as guidance rather than as the standard, and says so on every one of them. The success criterion is what conformance is measured against, and a technique is one documented way to meet it.