You
can combine multiple files from different applications in one operation
to create a single PDF. For example, you can combine word-processing
files with slide presentations, spreadsheets, and web pages. Choose
File > Create PDF > Merge Files Into A Single PDF.
During conversion, Acrobat opens each authoring application,
creates a tagged PDF, and assembles these PDFs into a single tagged
PDF.
The conversion process doesn’t always correctly interpret the
document structure for the combined PDF, because the files being
assembled often use different formats. Use Acrobat Pro or Acrobat
Pro Extended to create an accessible PDF from multiple documents.
When you combine multiple PDFs into one tagged PDF, it is a good
idea to retag the combined document. Combining tagged and untagged
PDFs results in a partially tagged PDF that isn’t accessible to
people with disabilities. Some users—such as those using screen
readers—will be unaware of the pages that don’t have tags. If you
start with a mix of tagged and untagged PDFs, tag the untagged files
before proceeding. If the PDFs are all untagged, add tags to the combined
PDF after you finish inserting, replacing, and deleting pages.
When you insert, replace, or delete pages, Acrobat accepts existing
tags into the tag tree of the consolidated PDF in the following
manner:
When you insert pages into a PDF, Acrobat adds the tags
(if any) for the new pages to the end of the tag tree. This order
occurs even if you insert the new pages at the beginning or the
middle of the document.
When you replace pages in a PDF, Acrobat adds the tags (if
any) from the incoming pages to the end of the tag tree. This order
occurs even if you replace pages at the beginning or the middle
of the document. Acrobat retains the tags (if any) for the replaced
pages.
When you delete pages from a PDF, Acrobat retains the tags
(if any) of the deleted pages.
Pages whose tags are out of order in the logical structure tree
can cause problems for screen readers. Screen readers read tags
in sequence down the tree, and possibly do not reach the tags for
an inserted page until the end of the tree. To fix this problem,
use Acrobat Pro or Acrobat Pro Extended to rearrange the tag tree.
Place large groups of tags in the same reading order as the pages themselves.
To avoid this step, plan on inserting pages to the end of a PDF, building
the document from front to back in sequence. For example, if you
create a title page PDF separately from the content, add the content
PDF to the title page PDF, even though the content document is larger.
This approach places the tags for the content after the tags for
the title page. The tags won’t need to be rearranged later in Acrobat
Pro or Acrobat Pro Extended.
The tags that remain from a deleted or replaced page don’t connect
to any content in the document. Essentially, they are large pieces
of empty tag tree sections. These unneeded tags increase the file
size of the document, slow down screen readers, and can make screen
readers present confusing results. For best results, make tagging
the last step in the conversion process. Use Acrobat Pro or Acrobat
Pro Extended to delete the tags of deleted pages from the tag tree.
For more information, see Create merged PDFs.
