Background Purpose I Instructions I

Background

Overlapping objects that obstruct content can create reflow problems in the generated PDF document and in some cases cause the PDF not to be generated correctly.

Purpose

This checkpoint allows the user to review each instance of overlapping objects to ensure content isn’t obscured and reading order is appropriate. When objects overlap they may present ambiguities to the authoring software, with unpredictable results in the output PDF file.

Instructions

The Current Checkpoint displays a list of detected overlapping objects.

  1. Select the object from the list.
  2. Ensure no content is obstructed by the object.
  3. If content is obstructed, close CommonLook Office and change the design so that no content is obstructed.

Picture of the CommonLook Office panel showing overlapping objects side by side with the word document.

For each instance of overlapping objects in which content is obstructed, the following options are available:

  • Group the objects (if you can). Each group will have a single tag in the resulting PDF.
  • Change the design so the objects no longer overlap. Each object will receive its own tag.
  • Leave the design as is. In the case in obstructed content, errors may occur. Some content belonging to one object may be tagged with another. Some content may become hidden in the physical view and still be readable in the logical view.

Note: It is highly recommended that overlapping objects be grouped and that alternative text is provided for the group as a whole. See Adding Alternative Text in MS Word.

Key Tip: When objects are obstructed (hidden) behind other objects the PDF may not be generated correctly. Each instance of such obscuring, if accepted in the checkpoint, should be checked in the generated PDF file. If a document fails to generate correctly due to an image overlapping with text, move that text to a separate textbox and group the new textbox with the image.

Guidelines and Standards

This checkpoint is relevant to the following regulations, guidelines and standards.

DocumentPublishedScopeConformance Criteria
US Section 508 (USA)2001“Web-Based Information & Applications”Paragraphs (d)
W3C WCAG 2.02008Web ContentSC 1.3.2
ISO 14289 (PDF/UA)2012PDF TechnologySection 7.1

 

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