PAC General information and worth to know about PDF standards

PDF standards

PAC checks the compliance of existing PDF documents with the PDF/UA standard.
It specifies how the underlying PDF standard must be applied to generate
accessible PDF documents.

The Matterhorn Protocol

The purpose of the the Matterhorn Protocol is to
promote the adoption of the PDF/UA standard.
It defines a set of test criteria that allow PDF documents
to be checked for compliance with the PDF/UA standard.

PDF/UA conformance requires validation of both syntax and semantic.

It should be noted that the Matterhorn Protocol contains,
in addition to automatically verifiable criteria,
those that rely on human judgment for validation.

The Matterhorn Protocol specifies a common set of
31 "Checkpoints" with 136 failure conditions, whereof

• 89 failure conditions can be checked by software, and


• 47 failure conditions usually require human judgment.

The PDF Accessibility Checker (PAC) is "PDF/UA-Ready" Freeware

The PDF Accessibility Checker PAC is a freeware program of
the Swiss foundation Access for all. Its use is free.

PAC is based on the Matterhorn Protocol and uses the protocol to
analyze the accessibility and inaccessibility of existing PDF documents,
but the implemented checks don't have a 1:1 mapping with
the Matterhorn Protocol.

While Matterhorn only has one checkpoint for appropriate tagging,
PAC has a check for every single type of structure element.

Based on this, PAC automatically checks 107 verifiable criteria.
This can be used to detect whether a PDF document complies with
the PDF/UA standard according to these criteria.

Note! Naturally, PAC can not take account of those test criteria in which a
judgmental assessment of a matter by a human being must be made.

PAC supports anyone who wants or need to create accessible PDF documents.
A quick test procedure generates an overview and detail report.
The latter locates the offending errors in the document.
To document, print or easily pass the results on to third parties,
PAC can export the overview report into an accessible PDF document.

Accessibility of websites to WCAG 2.0/2.1 and
PDF/UA compliant documents

The Web Content Accessibility Guidelines 2.0/2.1 (WCAG 2.0/2.1)
are the internationally recognized guidelines for accessible web offers.
Many national or supranational regulations (eg at EU level)
on the accessibility of web sites refer to WCAG 2.0/2.1.

Electronic documents provided for download on a web site are also covered
by WCAG 2.0/2.1 per se and must meet the applicable success criteria to comply
with WCAG 2.0/2.1 (Level A, AA or AAA).
Not all PDF/UA accessible PDF documents comply with WCAG 2.0/2.1.

Note! The technical implementation of accessible PDF
requires however the PDF/UA standard, not the WCAG.

The error message above is shown by PAC when a document lacks proper
internal structure tagging, which all Assistive Technology (AT) devices
(such as screen readers, PDF readers) depend entirely on to accurately
reproduce the contents of a PDF document.
Such a PDF document is thus syntacticly not correct.

Recommended action:
Do not publish the document on public facing websites.
Do not accept the document, return it to responsible instance
for remediation - Re-do it, do it right!

The success message above is shown by PAC when a PDF document
meets the syntactic requirements of the ISO standard PDF/UA.

It remains to verify that the document is also semantically correct.
When this requirement is also successful, the document can be published
as a PDF that is accessible for everyone on the entity's websites.

If your PDF document does not pass the PDF/UA validation:

• Contact NewFormat for advice on how to create accessible PDF

PAC Program Interface

1. The PDF file to be checked is dragged and dropped onto
   the button with the corresponding icon;
   Alternatively, the button can be activated to upload the document of
   choice via the file system to the PAC.
   After one or the other action, the test procedure is started immediately. (1)


2. The upper part of the user interface displays core data
   for the checked PDF document:
   title of the document, file name, (main) language of the document,
   number of tags, number of pages and file size. (2)


3. In the first tab PDF/UA
   (others are reserved for potential further developments of the PAC),
   the conclusion of the completed examination procedure is displayed first.
   
   If the audited criteria meet the requirements of PDF/UA, the conclusion is:
   The PDF/UA requirements audited by PAC are met, in the opposite case:
   This file is not PDF/UA compliant. (3)


4. The results of the test procedure are then presented in a tabular overview
   with four columns and eleven rows.
   In the first column ("Checkpoints"), the eleven checkpoints are named,
   each of which summarizes the result for several individual test criteria.
   
   The second column documents the number of verified and validated
   occurrences of a given checkpoint ("Pass") and
   the third column gives the number of warnings;
   In these cases a closer analysis is indicated. ("Warning").
   Finally, the fourth column names the number of cases that
   violated the PDF/UA standard ("Failed"). (4)



Below the summary table are six feature buttons,
five of which are reserved (populated) and another
reserved for potential enhancements of the PAC.

The occupied five feature buttons are the following:

5. Export PDF Report
   The overview table described above is exported as a barrier-free PDF file. (5)


6. Detailed Report:
   The detailed report differentiates the findings documented in
   the summary table in detail and allows a quick localization of
   the non-validated occurrences of certain elements in the PDF file. (6)


7. Screen Reader Preview:
   Screen reader preview allows the quality of the semantic information
   given as a "tag" to the PDF document
   (for example: X is a first order chapter heading, X is a subsection,
   X is a section, X is a listing, X is a Footnote, etc.) and visually quickly check
   the sequential logic of the reading sequence specified in the document. (7)


8. Display of Logical Structure:
   The logical structure shows the complete structure tree.
   Combined views can be used to check tag properties.
   You can display corresponding elements for a tag in
   the document or control the role assignments. (8th)


9. Document Statistics:
   The document statistics provides an overview of the structural elements used
   and indicates the number of occurrences in the document for each. (9)

What is the minute test?

• Quick test of a PDF document for accessibility


• For everyone feasible with free available tools


• First assessment of PDF/UA conformity (tendency)


• First assessment of the semantics of the document


• Examiner gets better and faster the more often
  he has performed a minute test

What is the minute test not?

• Final statement on conformity of a document with
  tillgänglighetstandarder PDF/UA, BITV or WCAG 2.0/2.1


• Experts test


• Field test


• Final quality assurance


• 100% statement on the accessibility of a document

How do I proceed?

Step 1: Automatic PDF/UA check with PAC

1. Download PDF Accessibility Checker (PAC) free test tool


2. Check PDF document:

Step 2: Quick look at the statistics of the document

Review the document statistics

The statistic in Figure 3 shows that (among other things)
the following elements are present in the document:

• Headings of levels 1, 2 and 3
    
• Pictures and captions (Figure, Caption)
    
• Lists (L, Lbl, LBody)
    
• Paragraphs (P)
    
• Table of Contents (TOC, TOCI)

This indicates that the most important elements are present
and it is probably a correctly tagged document.

A quick look at the statistics in Figure 4 shows that there are
no headings, no table of contents and no captions.
This does not support a structured document.
It seems to consist mainly of sections of text.

Step 3: Quick review of the screen reader preview

With the screen reader preview, you can check the structure of the document.
Each element (eg H1, P, L etc.) is highlighted in color.

System Requirements:

The following system requirements must be met:

• Windows Vista (SP 2), Windows 7 (SP 1),
  Windows 8, Windows 8.1, Windows 10


• Microsoft .NET Framework 4.5.1 or later

The PAC user interface is available in English and German.