What is Tagged PDF

Adobe FrameMaker FAQ

What is Tagged PDF?

Tagged PDF files incorporate information introduced in the new PDF 1.4 specification that identifies a publication's layout elements and contents and the visual relationships between them. This allows logical reflow of tagged PDF files during viewing on a broad range of devices with widely varying screen sizes. Tagged PDF files can be read on popular handheld computers and ultra-compact laptops as well as on many types of accessible viewing devices.