Hack 34 Multipurpose PDF 
Give readers many editions in one package
without tagging your PDF.
PDF makes a document portable by wrapping all its
resources into a neat, single package. As people desire more
features, more things get packed into the PDF. By attempting to make
one file do all things for all people, that one file becomes large
and unwieldy. Its portability begins to suffer.
In particular, Adobe has worked to add an information-oriented
XML-ish layer on top of its presentation-oriented PDF features. The
result is a single file that you can use for many purposes, such as
paper printing, handheld reading, accurate text-to-speech, and
accurate data extraction. However, creating these
tagged PDFs is a slow and expensive process. The
data layer is interwoven with the presentation layer, so accessing
the data is difficult. Consequently, your readers have few options
for utilizing this data. Finally, a tagged PDF file can grow to more
than twice the size of its untagged counterpart.
In general, I advocate distributing a separate edition for each
target medium. This is much easier on your readers and on your
workflow. Eating sushi requires two chopsticks. Planar geometry
requires five postulates. Some things shouldn't be
reduced too far; don't feel compelled to make one
edition do all things for all readers.
4.4.1 Tools, Not Rules
With that said, sometimes it makes sense to distribute multiple
editions as a single PDF. For example, you might want to use PDF
features such as encryption or digital signatures across all your
editions. Instead of tagging your PDF, consider packing
alternative editions into your PDF as
attachments [Hack #54] .
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Candidates for attachments include the HTML edition [Hack #36], spreadsheet-ready document
data [Hack #55], the handheld
edition [Hack #36], or even the
source document.
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The concept of different attachments for different purposes makes
more sense to readers than a single, shape-shifting (tagged) PDF.
Also, they will immediately understand the benefits of each
alternative edition. "HTML Edition"
means reflowing text, easy data extraction, and easy text-to-speech.
"Tagged PDF" means little to most
people, so you might add: " . . . that acts like
HTML sometimes. You own Acrobat, right?" You will
have a struggle on your hands, assuming your reader has that much
patience.
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