Tagged PDF files contain metadata which describe the document structure and the order of the different document elements (e.g. pictures, text blocks, columns, titles). This makes it easier to extract text or graphics from PDF files, and helps screen readers to present the file content in the correct order. Accessibility standards may require PDF files to be tagged.
The Tag panel is called from the Panel bar by the following tool:
If you do not see this tool, right-click in an empty area of the Panel bar and select it.
The Tag panel displays the document's tags in a tree-type structure. When navigating through the tree to verify if the order and hierarchy of the tags is appropriate, you can optionally have associated content nodes highlighted.
The tag menu (structure display and tag-associated operations) is accessible either by right-clicking a tree node or by using the Options menu at the top of the panel.
Tag menu and commands
Tagging-related commands include:
Add tags: A drop-down list offers Tag PDF and Retag Settings.
The Retag Settings dialog box offers the following:
Tag PDF - see above.
Tag annotations - if this option is marked, the annotations of the PDF will also be tagged.
Tag form fields only (accessible only when Tag annotations is selected) - use it to include only form fields in the tag tree, but no annotations of any kind.
Prefix and Postfix options for the retagging.
The Options drop-down list offers the following commands:
New Tag - creates a new tag at the current tag hierarchy position.
Cut - cuts the selected tag.
Paste - pastes the cut tag after the selected tag node.
Paste Child - pastes the cut tag under the selected tag.
Delete Tag - removes the selected tag.
Remove Empty Tags - removes empty tags from the selected branch.
Find and mark Similar - displays the Find Similar dialog box. Set the search threshold (Strict, Loose, or between), then click Find to perform the search for similar tags. Optionally, click Find settings to launch the Find Similar Attributes dialog box, where you may refine your search by specifying which font and text attributes to filter with. Select an attribute to use in the search or clear it to avoid.
Change Tag to Artifact - works on tags assigned to pictures. Turns the selected tag to an artifact, not to be processed by the text-to-speech engine. Provide Artifact Type and Attach to Side(s) in the Create Artifact dialog box, then click OK to confirm the operation.
Create tag from selection (only available after you have selected some PDF element with the Edit Object tool placed on the Edit > Modify ribbon) - inserts a new tag based on the selection.
Find - searches for all document elements such as Artifacts, Unmarked Comments, Unmarked Links, Unmarked Annotations, Unmarked Content that are not associated with any tag. You can search the current page or the entire document. Use it for manual tagging or verifying an existing tag structure by stepping through the located elements one by one.
Highlight Content - shows which file content is covered by the current tag.
Properties - displays the Object Properties dialog box. When you use it on a tag, it lets you edit the tag, attribute objects and classes. Using it on assigned content additionally lets you edit the container tag type and properties, or text attributes. It lets you view or change alternate texts or expansion texts for tagged objects. Alternate texts are used by screen readers to announce and describe graphic objects on the page.
Create tags root (only available for untagged PDFs) - creates the root object of the tag tree. This is the only menu item in the drop-down list under Options menu (at the top of the Tags panel) for a non-tagged PDF. Alternatively, right-click 'No tags available' and click this command. Use it to start building up a tag structure manually. Once the root is created, other commands become available in the drop-down menu.
Non-tagged PDF Documents
Some PDF files may not have a tag structure. In such cases, the Tags panel shows an empty tree with the description "No tags available". To create tags, you can either choose to add them to your document manually or to use the in-built layout analyzer.
To run the layout analyzer choose Tag PDF from panel toolbar
When layout analysis is complete, located tags - with reference to their contents - are added to the tree. You can review and modify it, or add missed non-textual elements (this latter operation has to be done manually). Once the PDF is tagged, the tag menu is available - see above.
Note
Tagged PDF can be made by PDF Create or tags in Word documents can be transferred to newly created PDF files.
Editing the content of a tagged PDF file, or deleting, inserting pages, damages the tag structure. Therefore if necessary, use the Tag PDF Tool that deletes the existing tag structure and creates a new one.
Moving to Advanced Edit mode may remove tags from a document.