Setting the reading order can be tricky in a PDF. There are several items to consider including the content panel, the z order panel, and tags panel.
Video Overview of how to set the reading order of a PDF
Match the content panel with the reading order panel
If you’re just starting, it’s best to start adjusting the content panel first. Then, you’ll move on to the read order panel and finish with the tags panel. Most assistive technology will follow the tags panel.
Open up the content view on the far left side (Important: Do not remove anything from the content panel. This could remove it from the document’s structure and cause issues with the document itself.).
Use the down arrow to follow the structure of the content to ensure everything is in the correct reading order.
If there’s anything out of place, move it to the correct spot in the content panel.
Once you’ve finished reordering things in the content panel, check the read order panel to see if the content was updated correctly.
Then, check the tags panel to see if the copy was updated.
Match the reading order panel with the tags panel
Once you’ve ensured everything is in the correct order in the content panel, you’ll want to adjust the reading order panel (z order panel). There are a couple of helpful tools in the reading order panel. Once you’ve selected the reading order panel, here’s how you’ll parse through it:
Select the accessibility button.
From there, select the reading order button.
Choose “Show page content groups” followed by the “Page content order” button in the Reading Order popup. By doing this, you’ll see display boxes of content with numbers on the page for easy viewing of the reading order.
Final Step
Walk the tags panel to ensure everything is in the correct order.
The make accessible action wizard is a tool that can help get a tag structure into a PDF so that you can begin making it accessible. This workflow can be implemented with almost any document. Important note: this process may overwrite any other work you have done in any other programs.
Add the Action Wizard from the tools menu
The first step is to ensure you have the proper tool setup in Adobe acrobat pro.
Tags are the basis for accessibility within a PDF. Without proper tags there is no accessibility. Tag elements provide semantic information for screen readers, control the reading order, and other important functions. An important first step is to determine if your PDF has tags. Review this post to find out if your document has tags.
Why do PDF tags matter?
Assistive technology will read tags and use them as a method for navigating larger documents. A tagged PDF is essential for those with visual disabilities and anyone who is using assistive technology like JAWS or NVDA.
PDF tags make it possible to identify content like headings, lists, links, tables, forms, and other important features. Not all programs can export a tagged PDF – so make sure you are using the right tools!
Sample screenshot of tags panel
Video overview of PDF Tags
Tag Relationships
Tags come in a pair and can sometimes be referred to as a Parent-Child relationships. In the example below the Figure tag is the parent tag and image container is the Child tag.
Every parent tag will have a child tag. This is useful for moving tags around in the tags panel.
The PDF Tags breakdown
If a tag is not properly categorized it will fail accessibility checks and be confusing to its users. Adding tags does not change the visual appearance of the document; it provides invisible layer of formatting within the document that works with screen readers. PDF tags also allows the content to reflow seamlessly on devices with smaller screens, like smartphones and tablets. Here is a brief explanation of what each tag represents:
<P>
The P tag is the most basic and universal tag. This tag is used as body text.
<H1> <H2> <H3> <H4> <H5> <H6>
These are heading tags. Most documents will have a single H1 tag, but larger documents could contain more. Modern assistive technology can recognize up to six heaving levels. Always use headings in order. Think of them like an outline.
The Parent Tag <H1>
The child tag (container)
The content the tag is referencing (content on page)
<L> <LI> <Lbl> <LBody>
List elements contain a specific structure. These tags represent the structure of accessible lists. Some accessibility guidelines require the use of Lbl and other guidelines do not.
List Parent Tag <L>
List Item Child Tag <LI>
Label <Lbl>
List Body child Tag <LBody>
Contents of First list item
List item content on page
<Figure>
The figure tag represents any and all images. At this time the figure tag is used for all graphics within a PDF.
<Figure> is a parent tag
The Image is a child tag (container)
The image as content on page
<Table> <TR> <TH> <TD>
Reading plain text is an easy task for assistive technologies. A table of data presents a complex more task. Proper PDF tag structure makes this possible by identifying essential information including the number of rows and columns as well as column (or row) headers, and which heading each data entry corresponds to. The more complex a table is, the more significant the challenge to tag it correctly.
Table Parent Tag <Table>
Table Row Child tag <TR>
Table Header Cell <TH>
Table Data Cell <TD>
Table on Page
<Link>, Link – OBJR
Every link tag needs a Link-OBJR tag.
Parent tag <P>
Link Tag <Link>
Link Reference Object
The link Text on screen
Content on page
<Reference> & <Note>
Reference and Note tags are up for interpretation but are commonly used within PDFs to “visually” break content apart.
Reading Order
An accessible PDF provides the instructions to the assistive technologies such as screen readers to read the content properly and in the correct order. The tag order within the tag tree will determine the reading order of the document. For documents without this logical structure, the best case would be that assistive technologies would guess at the correct order that the content should be presented in. In worst cases, the content would be completely unable to be read. The outcome is that the content becomes useless to the user.
How do I apply tags to a document?
There are multiple methods to apply tags to a document. The most common methods are:
Possible and semantically meaningful parent elements
Possible and semantically meaningful child elements
Document
Represents a complete document
–
Grouping elements, Block-level structure elements
Part
Division of a larger document into smaller, associated parts
Document
Art, Sect, Div, BlockQuote, Caption, TOC, Index,
Art
Parts of content which together are conclusive, i.e. an article or part of a document
Document, Part, Sect, Div, BlockQuote
Sect, Div, BlockQuote, Caption, TOC, Index,
Sect
Grouped related content parts, for example several paragraphs, which can be combined into a group
Document, Part, Art, Sect, Div, BlockQuote
Art, Sect, Div, BlockQuote, Caption, TOC, Index,
Div
Generic group element without semantic meaning
Document, Part, Art, Sect, Div, BlockQuote
Art, Sect, Div, BlockQuote, Caption, TOC, Index,
BlockQuote
One or more paragraphs that originate from another author, in other words, that have been quoted
Document, Part, Art, Sect, Div
Art, Sect, Div, Caption,
Caption
A caption to describe for example a picture or a table
Document, Part, Art, Sect, Div, BlockQuote, Table, L
Sect, Div, BlockQuote,
TOC
Container for table of contents entries. Can be used either as a flat hierarchy (all contained TOCI on one level) or as a complex hierarchy (TOC within a TOCI as a subgroup). Can be contained multiple times in a document, since it can also be used for image or table directories.
Document, Part, Art, Sect, Div
TOCI
TOCI
Entry within a table of contents (TOC).
TOC
TOC, P, Lbl, Reference
Index
Container for a subject index
Document, Part, Art, Sect, Div
L
Block-level structure elements
Paragraph elements
PDF tag
Semantic meaning
Possible and semantically meaningful parent elements
Possible and semantically meaningful child elements
Possible and semantically meaningful parent elements
Possible and semantically meaningful child elements
L
List container; groups together all list elements that belong together
Document, Part, Art, Sect, Div, BlockQuote, Index
LI, Caption
LI
Container of a list entry; can contain an L to create multi-level lists
L
Lbl, LBody, L
Lbl
Comes from the term “label” and represents the numbering or bullet character within a list. It’s not actually a block-level structure element and can also be used in other elements such as TOCI or Caption.
LI
–
LBody
Contains the contents of a list entry
LI
Inline-level structure elements
Table elements
PDF tag
Semantic meaning
Possible and semantically meaningful parent elements
Possible and semantically meaningful child elements
Table
Table container; combines all related table elements
Document, Part, Art, Sect, Div, BlockQuote
TR, Caption, THead, TBody, TFoot
TR
Groups a table row
Table, THead, TBody, TFoot
TH, TD
TH
Table heading cell; describes the meaning either at horizontal (line) or vertical (column) level
TR
Inline-level structure elements
TD
Ordinary table data cells
TR
Inline-level structure elements
THead
A group of table rows (TR) to mark them as table header; can be used optionally
Table
TR
TBody
A group of table rows (TR) to mark them as table content; can be used optionally
Table
TR
TFoot
A group of table rows (TR) to mark them as table footer; can be used optionally
Table
TR
Inline-level structure elements
PDF tag
Semantic meaning
Possible and semantically meaningful parent elements
Possible and semantically meaningful child elements
Span
Generic container without semantic meaning; is used, among other things, for visual markups, language changes or for adding ActualText (e.g. for ignoring hyphens)
P, H1–H6, LBody, TD, Quote, Note
–
Quote
Used like BlockQuote for quoted content; however, Quote is used at line level
P, H1–H6, LBody, TD
Span
Note
Footnote or endnote text (not the reference character in the body text). The footer/end-note character within Note and Reference will be placed in a Lbl.
P, H1–H6, LBody, TD
Lbl, P, Span
Reference
Refers to another place in the document, e.g. footnote or directory entry
P, H1–H6, LBody, TD
Lbl
Code
Marking of programming language
P, H1–H6, LBody, TD
–
Link
Link to a web page or to a place within the document
P, H1–H6, LBody, TD
–
Annot
Annotations that are not a link or a widget (form field), like comments and videos.
P, H1–H6, LBody, TD
–
Illustration graphic elements
PDF tag
Semantic meaning
Possible and semantically meaningful parent elements
Possible and semantically meaningful child elements
Do you ever have an image in your PDF that you need to OCR and make text? Adobe Acrobat has a feature called Scan and OCR which can do just that. This is useful for when you have a scanned image or poor-quality PDF.
Best practice
Try to avoid using images of text as this is a direct violation of accessibility guidelines. This is why the Scan and OCR feature is useful.
Video Overview of how to use the Scan and OCR feature in Adobe Acrobat
Text Overview of how to use the Scan and OCR feature
Select the scan and ocr tool
Select recognize text in this file
Select recognize text
How do I test to make sure that it worked?
The best method to ensure that your Scan and OCR worked is to try and copy and paste the text into another program. This will tell you that the OCR took place and will allow you to check for accuracy.
Im not sure I could keep count of the number of times I have been asked this question so here is a whole post dedicated to the topic!
Do not use the print to pdf function in MS Word. This will overwrite all of your hard work that you did in MS Word.
The Accessibility Guy
If you properly format your word document – you can export an almost perfect PDF file that will be close to passing accessibility requirements. By making a word document accessible, you can cut the time to remediate a PDF by more than 90%. Need some guidance on how to make Word documents accessible? The image below is a link to the Microsoft Word accessibility page.
Video Overview of how to convert from Word to PDF and retain the structure
Text Overview for how to set settings for export from Word to PDF
The majority of accessibility occurs in the tags panel but how do you know if your PDF has tags in it?
Important Note: You will need Adobe Acrobat Pro to determine if your document has tags in it. Tags provide the foundation for accessibility and PDFs. If your document is not tagged, it will not be read properly by screen readers and assistive technology.
Does my PDF have tags Video Overview
How to check if your PDF has tags?
There are a couple of ways to view if your PDF has tags in it.
Option 1
Open a document in adobe acrobat pro
Right click the far left side of the menu
Select tag
Option 2
Select View
Select Show / Hide
Select Navigational Panels
Select Tags
Your document will either say No Tags or you will see a list of tags available.
Document with no tags
This means that the document is not going to be read properly by assistive technology.
Document with tags
This example provides a tagged PDF with information that is passed onto assistive technology.
