Adobe 22002484 User Guide - Page 268

USING ACROBAT 9 STANDARD 263 Accessibility, tags, and reflow Tag the PDF Improve the accessibility of PDFs by adding tags in Acrobat. If a PDF doesn't contain tags, Acrobat attempts to tag it automatically when users read or reflow it, and the results may be disappointing. With a tagged PDF, the logical structure tree sends the contents to a screen reader or other assistive software or hardware in an appropriate order. For best results, tag a document when converting it to PDF from an authoring application. Examples of these applications include Adobe FrameMaker®, Adobe InDesign®, Microsoft Word, or OpenOffice Writer. If you do not have access to an authoring application that can generate a tagged PDF, you can tag a PDF any time by using Acrobat. Tagging during conversion to PDF requires an authoring application that supports tagging in PDF. Tagging during conversion enables the authoring application to draw from the paragraph styles or other structural information of the source document to produce a logical structure tree. The logical structure tree reflects an accurate reading order and appropriate levels of tags. This tagging can more readily interpret the structure of complex layouts, such as embedded sidebars, closely spaced columns, irregular text alignment, and tables. Tagging during conversion can also properly tag the links, cross-references, bookmarks, and alternate text (when available) that are in the file. To tag a PDF in Acrobat, use the Add Tags To Document command. This command works on any untagged PDF, such as one created with Adobe PDF Printer. Acrobat analyzes the content of the PDF to interpret the individual page elements, their hierarchical structure, and the intended reading order of each page. Then, it builds a tag tree that reflects that information. It also creates tags for any links, cross-references, and bookmarks that you added to the document in Acrobat. The Add Tags To Document command adequately tags most standard layouts. However, it cannot always correctly interpret the structure and reading order of complex page elements. These elements include closely spaced columns, irregular text alignment, nonfillable form fields, and tables that don't have borders. Tagging these pages by using the Add Tags To Document command can result in improperly combined elements or out-of-sequence tags. These issues cause reading order problems in the PDF. Create a tagged PDF from a web page A PDF that you create from a web page is only as accessible as the HTML source that it is based on. For example, if the web page relies on tables for its layout design, the HTML code for the table may not flow in the same logical reading order as a tagged PDF would require, even though the HTML code is sufficiently structured to display all the elements correctly in a browser. To produce the most accessible PDFs from web pages you create, first establish a logical reading order in their HTML code. For best results, employ the Web Content Accessibility Guidelines that are published by the World Wide Web Consortium (W3C). For more information, see the guidelines on the W3C website. 1 Do one of the following: • In Acrobat, choose File > Create PDF > From Web Page, enter the web page address, and then click Settings. • In Microsoft Internet Explorer, in the Adobe PDF toolbar, click the down arrow on the Convert button and choose Preferences. 2 In the General tab, select Create PDF Tags, and then click OK. 3 Specify any other options as appropriate, and then click Create. Creating a tagged PDF from an authoring application In most cases, you create tagged PDFs from within an authoring application, such as Adobe FrameMaker®, Adobe InDesign, or Microsoft Word. Creating tags in the authoring application generally provides better results than adding tags in Acrobat. Last updated 9/30/2011