Adobe ACROBAT 3D Manual page 375

Creating tagged Adobe PDF from authoring applications
In most cases, you create tagged Adobe PDF files from within an appropriate 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 Adobe Acrobat.
PDFMaker provides conversion settings that let you create tagged PDF documents in
Microsoft Excel, PowerPoint, and Word. (See About PDF conversion settings (Microsoft
Office files).)
In Acrobat, you can determine if a PDF document is tagged by viewing Document
Properties. For more information, see the documentation for your authoring application.