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Tab order failed: pages with annotations need /Tabs /S

Every page that contains links, form fields or other annotations must tell PDF viewers to move the keyboard focus in structure order. In the file this is the entry /Tabs /S in the page dictionary. Acrobat Pro sets it for all pages with the Fix command of its Tab order rule.

Updated

Messages you may see

  • Tab order - Failed (Acrobat Pro, Accessibility Checker)
  • PDF/UA-1 (ISO 14289-1) rule 7.18.3-1: A page with annotation(s) contains Tabs key with value … instead of S
  • PDF/UA-2 (ISO 14289-2) rule 8.9.3.3-1: A page with annotation(s) contains Tabs key with value … instead of A, W or S

What the rule requires

ISO 14289-1 (PDF/UA-1), clause 7.18.3, requires that every page on which there is an annotation contains the key Tabs in its page dictionary, with the value S. The Matterhorn Protocol 1.1 lists this under checkpoint 28 (Annotations). Automated checkers test it as rule 7.18.3-1 on each page that has an /Annots array.

Values of the Tabs entry and what PDF/UA accepts
Value of /TabsOrder of the keyboard focusPDF/UA-1PDF/UA-2
/SStructure order: the order of the elements in the tag treeallowedallowed
/RRow order: left to right, top to bottomnot allowednot allowed
/CColumn order: top to bottom, column by columnnot allowednot allowed
/AAnnotations array order: the order of the page's /Annots array (PDF 2.0)not allowedallowed
/WWidget order as defined in ISO 32000-2 (PDF 2.0)not allowedallowed
no entryUp to the viewernot allowednot allowed

PDF/UA-2 (ISO 14289-2, clause 8.9.3.3) accepts /A, /W or /S. The values /A and /W are defined only in PDF 2.0. For files checked against PDF/UA-1, only /S passes this rule.

The rule is machine-checkable, but it only states which order to use. Whether that order makes sense depends on the tag tree. If the tags are in the wrong order, /Tabs /S faithfully reproduces the wrong order. That part needs a manual check.

Why it matters

People who cannot use a mouse move through links and form fields with the Tab key. Screen reader users do the same in forms. If the order follows rows or the internal list of annotations, the focus can jump from the first column of a two-column page to the second and back, or from the last form field to a link in the header.

In forms this leads to wrong entries: a person fills in what they think is the postcode field, but the focus is already on the phone number. Adobe links the Tab order rule to WCAG success criterion 2.4.3 Focus Order. The W3C technique PDF3 describes the same requirement for tagged PDF.

Common causes

  • The program that created the PDF does not write a /Tabs entry. In Acrobat's Page Properties, the tab order then shows as unspecified.
  • Links, comments or form fields were added later in Acrobat or another program on pages that previously had no annotations.
  • Pages were inserted or merged from other files whose pages use row or column order.
  • A form was built with row order because that matched the visual layout at the time.

Example

A page with three annotations (two links and a form field) and no /Tabs entry. A PDF/UA check reports rule 7.18.3-1:

5 0 obj
<< /Type /Page /Parent 2 0 R
   /MediaBox [0 0 595 842]
   /Resources 7 0 R /Contents 6 0 R
   /Annots [31 0 R 32 0 R 40 0 R]
   /StructParents 0 >>
endobj
Failing: page with annotations, no Tabs entry
5 0 obj
<< /Type /Page /Parent 2 0 R
   /MediaBox [0 0 595 842]
   /Resources 7 0 R /Contents 6 0 R
   /Annots [31 0 R 32 0 R 40 0 R]
   /StructParents 0
   /Tabs /S >>
endobj
Passing the machine check: Tabs set to structure order

With /Tabs /S, a viewer moves the focus in the order in which the Link and Form elements for annotations 31, 32 and 40 appear in the tag tree, not in the order of the /Annots array.

How to fix it

Microsoft Word

Word's PDF options contain no setting for the tab order. What Word writes depends on the version, so check each exported file.

  1. Choose File > Save As or File > Save a Copy, select PDF, then Options.
  2. Keep Document structure tags for accessibility selected and save.
  3. Check the new PDF. If the Tab order finding remains, set the tab order in Acrobat Pro as described below.

Links and the table of contents are the usual annotations in Word PDFs. Microsoft documents that Word exports header and footer content as artifacts without tags; a link in a header or footer is therefore a common source of other link findings as well.

Adobe InDesign

For interactive PDFs, InDesign has an export option that applies the tab order you set in the document.

  1. Set the order of buttons and form fields per page with Object > Interactive > Set Tab Order.
  2. Choose File > Export and Adobe PDF (Interactive).
  3. On the General tab, switch on Create Tagged PDF and Use Structure for Tab Order. Adobe notes that the second option is available only for tagged PDFs.
  4. Check the exported file. If pages exported with Adobe PDF (Print) still fail, set the tab order in Acrobat Pro.

For forms, Adobe also describes setting the order in the Articles panel (Window > Articles) and choosing the option to use it for the tagged PDF from the panel menu. The name of that menu item differs between InDesign versions.

Adobe Acrobat Pro

Fix all pages through the Accessibility Checker

  1. Choose All tools > View more > Prepare for accessibility > Check for accessibility and start the check.
  2. In the results panel, open Page Content and select Tab order.
  3. Open the options menu (…) of the rule and choose Fix. Acrobat sets the tab order to the document structure.
  4. Choose Recheck to confirm.

Set the tab order manually

  1. Open the Page Thumbnails panel.
  2. Select a page thumbnail and choose Page Properties from the options menu.
  3. On the Tab Order tab, select Use Document Structure and select OK.
  4. Repeat for every page that contains links, form fields or comments.

Then check the order in the Tags panel or with the Reading Order tool: the order of the Link and Form tags is the order in which the Tab key now moves.

Check your PDF

Upload the fixed file to see which machine-checkable criteria it meets now. The report lists the remaining problems with their pages.

Open the checker

Questions

Does /Tabs /S change the reading order?
No. The reading order comes from the tag tree. /Tabs /S tells the viewer to use the same order for the keyboard focus.
Do pages without links or form fields need the entry?
No. The rule applies only to pages that contain at least one annotation. Setting it on all pages does no harm.
Should I use /A or /W in a PDF/UA-2 file?
PDF/UA-2 allows them, but then the order of the /Annots array must match the logical order. /S follows the tag tree, which you have to check anyway, so it is usually the simpler choice.

Sources

  1. ISO 14289-1:2014 – Document management applications – Electronic document file format enhancement for accessibility – Part 1: Use of ISO 32000-1 (PDF/UA-1) – International Organization for Standardization (ISO). Checked on 7 November 2026.
  2. ISO 14289-2:2024 – Document management applications – Electronic document file format enhancement for accessibility – Part 2: Use of ISO 32000-2 (PDF/UA-2) – International Organization for Standardization (ISO), 13 March 2024. Checked on 7 November 2026.
  3. The Matterhorn Protocol 1.1 – PDF Association. Checked on 7 November 2026.
  4. Create and verify PDF accessibility (Acrobat Pro) – Adobe (helpx.adobe.com). Checked on 7 November 2026.
  5. PDF3: Ensuring correct tab and reading order in PDF documents – World Wide Web Consortium (W3C), Web Accessibility Initiative. Checked on 7 November 2026.
  6. Interactive PDF options (InDesign) – Adobe (helpx.adobe.com), 2 June 2026. Checked on 7 November 2026.
  7. Create fillable forms (InDesign) – Adobe (helpx.adobe.com), 2 June 2026. Checked on 7 November 2026.
  8. Create accessible PDFs – Microsoft Support. Checked on 8 November 2026.
  9. Word PDF Accessibility – Microsoft Learn, 12 May 2026. Checked on 8 November 2026.