Correct reflow problems with the Content panel
Use the Content panel to correct reflow problems in a PDF that can’t be corrected by using the Reading Order tool. Because you can damage a PDF by editing content objects, make sure that you’re familiar with PDF structure before you change anything. For comprehensive information about PDF structure, see the PDF Reference Sixth Edition: Adobe Portable Document Format Version 1.7, on the PDF reference page (English only) of the Adobe website.
The Content panel provides a hierarchical view of the objects that make up a PDF, including the PDF object itself. Each document includes one or more pages, a set of annotations (such as comments and links), and the content objects for the page. The content objects consist of containers, text, paths, and images. Objects are listed in the order in which they appear on the page, like tags in the logical structure tree. However, PDFs don’t require tags for you to view or change the object structure.
- Drag it to the location you want.
- Choose Cut from the options menu, select the tag above the location you want to paste the cut tag, and choose Paste from the options menu.
Container elements can’t be pasted directly to page elements. To move a container to another page, cut the container you want to move. Then select a container on the page you want to move the container to and choose Paste from the options menu. Then, drag the container out one level to the location that you want.
In the Content panel, use the options menu or right-click an object to choose from the following options:
Edit Container Dictionary
Specifies the dictionary for the container. Errors in this dialog box may damage the PDF. Available only for containers that include dictionaries.
Find Content From Selection
Searches for the object in the Content panel that contains the object selected in the document pane.
Searches for unmarked (untagged) artifacts, content, comments, and links. Options allow you to search the page or document, and to add tags to found items.
Defines selected objects as artifacts. Artifacts are not read by a screen reader or by the Read Out Loud feature. Page numbers, headers, and footers are often best tagged as artifacts.
Show In Tags Panel
Switches automatically to the Tags panel, and selects the tag corresponding to the content element.
When selected, highlights appear in the document pane around content that relates to a selected object in the Content panel.
The Tags panel allows you to view and edit tags in the logical structure tree, or tags tree, of a PDF. In the Tags panel, tags appear in a hierarchical order that indicates the reading sequence of the document. The first item in this structure is the Tags root. All other items are tags and are children of the Tags root. Tags use coded element types that appear in angle brackets (< >). Each element, including structural elements such as sections and articles, appears in the logical structure order by type, followed by a title and the element’s content or a description of the content. Structural elements are typically listed as containers (parent tags). They include several smaller elements (child tags) within them.
For more information on logical structures, see the PDF Reference Sixth Edition: Adobe Portable Document Format Version 1.7, on the PDF reference page (English only) of the Adobe website.
Though you can correct most tagging issues by using the Reading Order tool, you must use the Tags panel to address detailed tagging of tables and substructure items, such as paragraphs, lists, and sections that require multiple languages. Add tags manually to a document in the Tags panel only as a last resort. First consider using the Add Tags To Document command.
Operations performed in the Tags panel cannot be undone with the Undo command. Save a backup copy of a document before you begin work on it in the Tags panel.
You can edit a tag title, change a tag location, or change the tag type for an element. All page content must be tagged, marked as an artifact, or removed from the logical structure tree.
- Drag the tag to the location you want. As you drag, a line appears at viable locations.
- Choose Cut from the options menu, and select the tag that appears above the location you want to paste the cut tag. From the options menu, choose Paste to move the tag to the same level as the selected tag. Or choose Paste Child to move the tag within the selected tag.
In the Tags panel, use the options menu or right-click a tag in the logical structure tree to choose from the following options:
Creates a tag in the logical structure tree after the currently selected item. Specify type and title of the new tag.
Places the tag that’s on the clipboard into the location specified, replacing the selected tag.
Places the tag that’s on the clipboard into the location specified, as a child of the selected tag.
Find Tag From Selection
Searches for the tag in the Tags panel that contains the text or object selected in the document pane.
Create Tag From Selection
Creates a tag in the logical structure tree after the item selected in the document pane. Specify type and title of the new tag.
Searches for artifacts, OCR suspects, and unmarked (untagged) content, comments, links, and annotations. Options allow you to search the page or document and add tags to found items.
Change Tag To Artifact
Changes selected tags to artifacts and removes the tagged content from the structure tree.
Edit Class Map
Allows you to add, change, and delete the class map, or style dictionary, for the document. Class maps store attributes that are associated with each element.
Edit Role Map
Allows you to add, change, and delete role maps for the document. Role maps allow each document to contain a uniquely defined tag set. By mapping these custom tags to predefined tags in Acrobat, custom tags are easier to identify and edit.
When selected, all new comments and form fields are added to the tag tree after the selected tag element. Existing comments and form fields aren’t added to the tag tree. Highlight and Underline comments are automatically associated and tagged with the text that they annotate and don’t require this option.
This option doesn’t necessarily indicate that the PDF conforms to PDF guidelines and should be used judiciously.
When selected, causes highlights to appear around content in the document pane when you select the related tag in the Tags panel.
Opens a read-only dialog box that contains reference information about the selected tag.
Some tagged PDFs might not contain all the information necessary to make the document contents fully accessible. For example, if you want to make a document available to a screen reader, the PDF should contain alternate text for figures, language properties for portions of the text that use a different language than the default language for the document, and expansion text for abbreviations. Designating the appropriate language for different text elements ensures that the correct characters are used when you repurpose the document and that it is spell-checked with the correct dictionary.
You can add alternate text and multiple languages to a tag from the Tags panel. (If only one language is required, choose the language with File > Properties instead.) You can also add alternate text by using the Reading Ordertool.
Keep alternate text descriptions as concise as possible.
Screen readers can read the URLs of web links out loud, but adding meaningful alternate text to links can help users immensely. For example, by adding alternate text you can have a screen reader tell a user to “go to the Acrobat accessibility page of adobe.com” rather than “go to http://www.adobe.com/products/acrobat/solutionsacc.html.”
You add alternate text to the <Link> tag of a link.
Add alternate text only to tags that don’t have child tags. Adding alternate text to a parent tag prevents a screen reader from reading any of that tag’s child tags.
When you tag a PDF that includes comments, the comments are tagged as well. However, if you add comments to a PDF that’s already tagged, your comments are untagged unless you enable comment tagging first.
To Enable comment tagging in a PDF, in the Tags panel, choose Tag Annotations from the options menu. Comments or markups that you add to the PDF are tagged automatically.
If a document contains untagged comments, you can locate them in the logical structure tree and tag them by using the Find command in the Tags panel.
Use the Reading Order tool to make sure that tables are tagged correctly. If you need to structure figures and text within the cells of your table, you may prefer to re-create the table in the authoring application before you convert it to an accessible PDF. Adding tags on a cell level in Acrobat is a labor-intensive procedure.
Before you make any changes to table elements, use the Reading Order tool to determine that the table is tagged correctly.
- If the tag for the table doesn’t contain these elements, but rows, columns, and cells appear in the table in the document pane, use the Reading Order tool to select and define the table or individual cells.
- If the table contains rows that span two or more columns, set ColSpan and RowSpan attributes for these rows in the tag structure.
- Re-create the table in the authoring application, and then convert it to a tagged PDF.
This section describes the standard tag types that apply to tagged PDFs. These standard tags provide assistive software and devices with semantic and structural elements to use to interpret document structure and present content in a useful manner.
The PDF tags architecture is extensible, so any PDF document can contain any tag set that an authoring application decides to use. For example, a PDF can have XML tags that came in from an XML schema. Custom tags that you define (such as tag names generated from paragraph styles of an authoring application) need a role map. The role map matches each custom tag to a standard tag here. When assistive software encounters a custom tag, the software can check this role map and properly interpret the tags. Tagging PDFs by using one of the methods described here generally produces a correct role map for the document.
You can view and edit the role map of a PDF by choosing Options > Edit Role Map in the Tags panel.
The standard Adobe element tag types are available in the New Tag dialog box. They are also available in the Touch Up Properties dialog box in Acrobat Pro. Adobe strongly encourages using these tag types because they provide the best results when tagged content is converted to a different format. These formats include HTML, Microsoft Word, or an accessible text format for use by other assistive technologies.
Block-level elements are page elements that consist of text laid out in paragraph-like forms. Block-level elements are part of a document’s logical structure. Such elements are further classified as container elements, heading and paragraph elements, label and list elements, special text elements, and table elements.
Container elements are the highest level of element and provide hierarchical grouping for other block-level elements.
Part element. A large division of a document; may group smaller units of content together, such as division elements, article elements, or section elements.
Section element. A general container element type, comparable to Division (DIV Class=“Sect”) in HTML, which is usually a component of a part element or an article element.
Heading and paragraph elements are paragraph-like, block-level elements that include specific level heading and generic paragraph (P) tags. A heading (H) element should appear as the first child of any higher-level division. Six levels of headings (H1 to H6) are available for applications that don’t hierarchically nest sections.
List element. Any sequence of items of similar meaning or other relevance; immediate child elements should be list item elements.
List item element. Any one member of a list; may have a label element (optional) and a list body element (required) as a child.
Label element. A bullet, name, or number that identifies and distinguishes an element from others in the same list.
Block quote element. One or more paragraphs of text attributed to someone other than the author of the immediate surrounding text.
Index element. A sequence of entries that contain identifying text and reference elements that point out the occurrence of the text in the main body of the document.
Table of contents element. An element that contains a structured list of items and labels identifying those items; has its own discrete hierarchy.
Table of contents item element. An item contained in a list associated with a table of contents element.
Table element. A two-dimensional arrangement of data or text cells that contains table row elements as child elements and may have a caption element as its first or last child element.
Table row element. One row of headings or data in a table; may contain table header cell elements and table data cell elements.
Table header cell element. A table cell that contains header text or data describing one or more rows or columns of a table.
Inline-level elements identify a span of text that has specific formatting or behavior. They are differentiated from block-level elements. Inline-level elements may be contained in or contain block-level elements.
Quote entry element. An inline portion of text that is attributed to someone other than the author of the text surrounding it; different from a block quote, which is a whole paragraph or multiple paragraphs, as opposed to inline text.
Span entry element. Any inline segment of text; commonly used to delimit text that is associated with a set of styling properties.
Similar to inline-level elements, special inline-level elements describe an inline portion of text that has special formatting or behavior.
Link entry element. A hyperlink that is embedded within a document. The target can be in the same document, in another PDF document, or on a website.
Note entry element. Explanatory text or documentation, such as a footnote or endnote, that is referred to in the main body of text.
Reference entry element. A citation to text or data that is found elsewhere in the document.