PDF (adobe.com)

Adding structure to PDFs

When you export to Adobe PDF with the Create Tagged PDF option selected in the General area of the Export Adobe PDF dialog box, the exported pages are automatically tagged with a set of structure tags that describe the content, identifying page items such as headlines, stories, and figures. To add additional tags or to fine-tune existing ones before you export, you can use the Tags panel in InDesign. The Structure pane (View > Structure > Show Structure) reflects the changes.

You can improve the accessibility and reuse of Adobe PDF documents by adding tags to the InDesign document before you export. If your PDF documents don’t contain tags, Adobe Reader or Acrobat may attempt to automatically tag the document when the user reads or reflows it, but the results may be disappointing. If you do not get the results you want in the exported PDF file, you can use tools in Acrobat 6.0 Professional and later to edit the structure of tagged PDF documents. For the most advanced tools, use Acrobat 9 Professional.

When you apply tags to a document for PDF export, the tags do not control which content is exported to PDF, as is the case with XML export. Instead, the tags give Acrobat more information about the document’s structural contents.

Advantages of using tags

By applying tags to your document before exporting to PDF, you can do the following:

  • Map InDesign paragraph style names to Acrobat tagged Adobe PDF paragraph styles to create a reflowable PDF file for viewing on handheld devices and other media.

  • Mark and hide printing artifacts, text, and images so that they won’t appear when reflowed in Acrobat. For example, if you tag a page item as Artifact, the page item will not be displayed when you reflow the contents of a tagged Adobe PDF document on a handheld device, a small display, or a monitor at a large magnification.

  • Add alternative text to figures so that the text can be read aloud to the visually impaired with screen-reading software.

  • Replace graphic letters, such as ornate drop-caps, with readable letters.

  • Provide a title for a set of articles, or group stories and figures into articles.

  • Order stories and figures to establish a reading order.

  • Recognize tables, formatted lists, and tables of contents. Recognize which content blocks belong to the different stories.

  • Include text formatting information such as Unicode values of characters, spacing between words, and the recognition of soft and hard hyphens.