# Why did they put PDF titling in the hyperref package?

The ability to title/attach an author to a published PDF file is in \hypersetup which is part of package hyperref. But it seems rather unintuitive to me that the pdftitle, pdfauthor, pdfsubject items are part of the hyperref package. Why is that?

A reason I can think of that they might have done this is because search engines will crawl through that data?

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I don't know if this question really has an answer. The hyperref package is written by Sebastian Rahtz and Heiko Oberdiek, although I think it's mainly Heiko's project now, so there isn't really a "they". Many of his packages make use of specific properties of pdf, presumably because of his interest in and knowledge of pdf, and that's probably why he put it into the package. – Alan Munn Aug 25 '11 at 1:11
PDF meta content is not localized to the hyperref package. See How can I generate PDF metadata from LaTeX? that describes using \pdfinfo{...} with /<meta-tag> operations/definitions. – Werner Aug 25 '11 at 17:24

From my reading of OP's question, it sounds like he's asking, if Latex as an overall collection of software/ utilities were made by one person or group, why would they choose to put PDF titling in hyperref, a package seemingly with the more concise goal of providing hyper referencing?

So, the best answer might be to point out that Latex is a collections of SW/ utilities/ tools made by many independent groups, usually working without a higher-level organizing structure.

So, in this case, I suspect that kind of like Alan said above, whoever made hyperref probably felt this PDF titling/ author listing functionality wasn't easily accessible in any other package, and figured that since they knew how to do it anyway, they'd just throw it into hyperref.

It's not that somebody explicitly said "I'm going to put PDF titling in hyperref rather than some other more obvious package."

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Indeed, when LaTeX2e was written, DVI output was standard and PDF meta-data was not really something to consider. – Joseph Wright Aug 25 '11 at 7:46
further to joseph's comment, i would point out that hyperref predates the use of pdftex as a main-line facility (though i don't doubt sebastian rahtz knew it was in the pipeline). fwiw, the hyper package (written at approx the same time hyperref started) seems to do hyper-features without titles and things; but it only works with dvi output and dvips \special commands. – wasteofspace Aug 25 '11 at 19:08

Actually PDF titling can be done using pdfLaTeX without any additional package. For example:

\documentclass{article}
\pdfinfo{
/Title (thesis.pdf)
/Creator (TeX)
/Producer (pdfTeX 1.40.0)
/Author (Stefan)
/Subject (Artificial intelligence and self-modifying TeX documents)
/Keywords (pdflatex,latex,pdftex,tex)}
\begin{document}
text
\end{document}


Hyperref provides an additional interface. Moreover, it can be used in DVI mode, encapsulating the PDF meta information by special commands within the DVI file, appearing in the PDF after conversion to PDF.

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Indeed, the pdftitle, pdfauthor, and pdfsubject fields are there to provide metadata, that can be used by search engines, but also your own operating system.

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When thinking about meta data, also hyperxmp and xmpincl packages come to mind, to generate/include xmp information in the pdf file. (From the question I got it that information should be included in a pdf file, and that it was not a complaint about a package being able to do this.)

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