Cleaning up the order of a tag tree in a lengthy PDF or the item list in structure tree of an InDesign file can be a time consuming job, particularly if there are a number of graphic objects in the file. InDesign places objects in the structure in their order of creation. In most cases, graphic items aren’t added to the file until after the main body of the text has been flowed. This places the graphic objects at the end of the structure, and they must be moved to their correct locations to end up with a compliant tag tree in the PDF.
Anchoring your graphics to their correct text locations substantially simplifies this process. Starting with InDesign CS5.5, Adobe has made frame anchoring much simpler than the convoluted process you had to go through in previous versions in order to anchor frames.
All non-linked frames and grouped frames now have a blue handle on the top right side. Simply dragging this handle to the correct text location anchors the frame to that location. When you export the tagged PDF from the InDesign file, the graphic shows up in the correct location in the tag tree.
There are some things you need to consider when placing these anchors:
- Since the graphic will likely have alternate text that will be read when the text reader reaches the graphic, you should place the graphic where the alternate text will not disrupt the logical flow of the text. For instance, if there is a call out for a figure in the middle of a sentence, you probably would not want alternate text read until the end of the sentence. You would likely place the anchor point at the end of the sentence or the end of the paragraph.
- The anchor point needs to be placed on the same page as the location of the graphic. This means that if a call-out is on a page preceding or following the page the graphic is on, you will need to anchor to some logical point on the same page as the graphic. If there is no text to anchor to on the page with the graphic, then you cannot anchor the frame.
- It is not unusual to receive files where separate frames containing the title of a graphic, the graphic itself, and notes following the graphic are all grouped together. Before anchoring a graphic, the individual frames need to be ungrouped if you want a text reader to read the title and notes. You can then anchor each one of the frames containing the title, the graphic, and the notes to the same location in their proper order. If you leave the items grouped, you end up with one figure item in the PDF’s tag tree. The title and notes are not available to be read by the text reader.