Talk:Portable Document Format/Archive 2

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Archive 1 Archive 2 Archive 3

Different Versions?

What is the difference between PDF 1.2, PDF 1.3, PDF 1.4, PDF 1.4, PDF/X and PDF/A?--Hhielscher 05:34, 16 September 2005 (UTC)

  • A full reply to this would run to over 1000 detailed pages, so to summarise: the numbered versions are those produced by Adobe. Each version of Acrobat is usually accompanied by a new version of PDF. Each revision is a superset of the previous one. PDF/X is a number of standards (five to date), each of which is a limited subset of PDF. The aim of limiting what can be in a PDF is to make PDF more reliable when used to carry information to professional printing. PDF/A is a different subset designed for long term archival. Notinasnaid 14:20, 17 September 2005 (UTC)
maybe a section detailing the main differences in each spec might be useful? Or a small articles? --Blade 21:28, 18 January 2006 (UTC)
  • I agree. A simple table would suffice highlighting the major features. Like "layer support", "overlay modes supported", "128-bit encryption", etc. -- 23:39, 20 November 2006 (UTC)

There is a table similar to what you descibe on the Adobe Acrobat page. Perhaps it could be adapted. Cornlad 19:15, 23 November 2006 (UTC)

"Unfree" standard

I've frequently heard accusations that PDF was a somehow "unfree" standard, less free than PostScript. Generally, those who say such things cannot point to specifics, so it's purely hearsay. What are the bases of these claims? Are there patents that encumber good quality rendering of PDF files, for instance? David.Monniaux 16:43, 25 October 2005 (UTC)

I think the spec used to be closed. Not sure about that though.

Camelot paper

Of interest : The 1991 seminal paper from John Warnock about 'Camelot', the Adobe code-name for PDF. -- 12:57, 21 February 2006 (UTC)

(Note: I moved this to the end of the message, since the convention is to add new items to the end). The Camelot Paper was already referred to in the article (under "Format info"). Notinasnaid 13:41, 21 February 2006 (UTC)


Would it be nice to include anything on PDF forms? It's quite a distinctive function of the format, I believe.


I suggest adding a very nontechnical section for users like me. Like on what it will do and what might be going wrong if it is not working. Or a link. Thanks. Richard L. Peterson 4/12/06

Bear in mind this article is about the PDF file format. It isn't about the software that you might be having problems with. Notinasnaid 17:41, 12 April 2006 (UTC)

Link removal

There has been a link to a site that's specifically geared towards the non technical user, that does offer free help and support, free tools, free membership, has absolutely NO commercial association with enterprise solution vendors, much less the vendors of overpriced print drivers. However, Notinasnaid, keeps removing it. Aparently he/she/it is on the payroll of one of those commercial sites as they're the only ones that have anything to lose if a site that offers absolutely everything for free is listed in the external links section. Also explains why Notinasnaid has no reference to a real name and has no website or email to identify him/her/it. Makes me wonder; who is wikipedia serving now, the average every day user who really needs the help they can't get anywhere else affordably, or the vendors who only help for a price?

First, thank you for stopping, after six attempts, adding this link and discussing. That's a good first step. I think you are probably new to editing Wikipedia, so a few points might be useful to reiterate. If removing your link was a mistake I apologise. First, Wikipedia is under attack by commercial spammers who add thousands of links each day in the hope of boosting their Google ratings. This tends to make editors extremely trigger happy in removing external links. Second, if a link is added by someone with no editing history... who has not shown themselves to be an editor who adds reasonable and relevant context, hopefully to a wide variety of articles... then it is especially likely the link will be hit. In such a case it is also extremely likely that the person posting the link is just using Wikipedia to promote their site: under the reasonable (but mistaken) assumption that Wikipedia is a free link farm. Generally you should never add a link to your own site, because it is impossible to be dispassionate about it (as I think your comments above rather show). If a site is notable enough, someone else will add it. Thirdly, Wikipedia does have policies that are relevant here: please read Wikipedia:External_links. Fourthly, this section is supposed to be about "format information" i.e. information about the PDF file format, not PDF tools or utilities.
Above all, if you are upset that the link is removed, it very strongly suggests you are upset that you cannot use Wikipedia to promote your site, so that is the strongest possible reason to remove it. That's not the only reason. You may indeed be an honest fan of the site.
Now, before deleting the link I did visit the site. Anyway, here's what I thought about the site when I visited it. Potential to be a good minor PDF portal, one day. Very early days, still full of "our first" articles. Baffling "Best sellers in PDF and eBook publishing" links which make it look like one of the countless sites selling eBooks, but links go nowhere. Very slow news section, only two additions this year.
I looked at the other two PDF portals listed, PlanetPDF and PDFZone. I know they have both been around over 7 years, and have (at least on occasion) employed journalists to provide copy and keep the news up to date. Both are commercial organisations, but the sites have large amounts of real information. PlanetPDF has around 50 news stories this year.
However, there remains a question about whether they are suitable for being external links. PlanetPDF was added with a comment that it has articles about developing with the PDF format; doubless true, somewhere.
The developer articles are clearly found on planetPDF: the link is under developer at the top of the page, then the articles are in tips & tricks. There is also a very useful forum on that site so I think it is a good site to link to. user:Danio
PDFZone was added with an entirely unsuitable description of being about PDF tools. Overall, I don't think either really belongs, but as they contain useful stuff I wasn't motivated enough to remove them.
What happens now? This may surprise you. We (the editors of this page) try to reach Consensus on what to do. So, comments please. Notinasnaid 08:15, 29 April 2006 (UTC)

First, thanks for the very complete reply and my apologies for the tone, somewhat out of frustration at knowing how to contact you aside getting your attention on an "open" page and no one to direct my questions to. I've also seen some of the sort of volunteer corruption I brought up in that post at dmoz over the years, not just by businesses, but some forms of elite-ism or fanatical ideologues and zealots et al. I really hope that isn't going to happen here...

Also a little upset at having it called spam, it's about the least commercial site I've ever built, barring a few sites for schools and charities. If anything, the site was built in the same spirit as wikipedia, all that's really missing is you, or people like you to volunteer articles, how tos, etc. I do what I can without compensation, I didn't build it for that. However, I do understand the spam problem, had to turn trackback functions off for the links to porn and gaming the site was getting, didn't think they'd hit you here though, sorry to hear that.

To address some of your other comments specifically;

"Very early days" - true, without people like you or Ziff Davis Media's (owners of one of those other portals) deep pockets to add content continually, it's slow going, but it chugs along and helps the people that ask for help, most of whom are the same ones that the other portals ignore, they don't have a lot of money to spend. They're also the sorts most likely to get ripped off by some unscrupulous marketers (possibly the same types that spam these pages also) selling what are essentially free print drivers for $20, $40, even seen them at $97. A rather disgusting practice I'm hoping I can put a dent in through a site like this, one of my primary reasons for bothering with it in the first place.

The "bestsellers" section is a feed from one of the web's largest processors of pdf books, site users can tell at a glance what topics are doing well. On occasion what's on the other end is down or something, I have no control over that, but usually there's book on sale at the other end and a publisher can go check it out. There's a lot of data out of that section I could publish, but don't have time, feel free to volunteer :)

"Potential to be a good minor PDF portal, one day." Thanks, do what I can. "I looked at the other two PDF portals listed, PlanetPDF and PDFZone." Good, then I suspect you'll understand the hole I'm trying to fill; one focuses on enterprise solution providers and developers, the other on the midrange businesses. Both are pretty good at serving their intended audiences, both fail to address the bottom end of the ladder, those with very limited budgets (sometimes nothing) and those with very limited prior knowledge. They deserve to be served too, don't they?

In conclusion, may I suggest a separate section in external links? For all 3 portals that cover the full spectrum of end user; high, middle and independent. I apreciate that the wiki entry is primarily a fairly basic dry/academic encyclopedia entry on the format, it's that much more useful if it helps people find what they need beyond that it seems. I will not add the site again, I sincerely hope you will, with a thought to the different audiences that pass through these pages, the volume from here isn't that high, however, I've noticed they're the ones most likely to participate in it as a community.

And for the record, I didn't initially add my own site, a member, now friend and employee of one of the large commercial entities (they all have employees in my membership) added it initially, supporters of open source are everywhere.

Thank you again for your time and response, sorry if this was a little long, but your own full post deserved a full reply. Feel free to contact me through the site if you wish. 20:32, 1 May 2006 (UTC)David.

Generally speaking something doesn't have to be commercial to be considered spam on wikipedia. Nil Einne 08:52, 18 November 2006 (UTC)


I do not think that pdf is proprietary any longer. I notice other companies offering "PDF writers" for sale. I know that Adobe has a lot of patents that have some bearing on PDF. But it appears to now be an open standard.

Nothing has changed. It all depends on exactly how anyone defines "proprietary" (i.e. some people use it to mean "secret" and other people use it to mean "controlled by a private company"). PDF has been fully documented in a book since the very first version of Acrobat. Notinasnaid 21:21, 29 May 2006 (UTC)
Yeah, I think the article could perhaps be rephrased as those sentences do sometimes give the wrong impression: the intellectual property on the PDF format is owned by Adobe, and they control what features go into any new versions of it - but nonetheless the PDF format is fully publically documented by them, with the intention that anyone else can use it and third party developers can write PDF-creating utilities or PDF-display viewers. It's not like, say, Microsoft's ".doc" and ".xls" formats for Word and Excel, which are secret.
"the intellectual property on the PDF format is owned by Adobe" Are you sure? PDF reading and writing is implemented in lots and lots of copylefted software, such as ghostscript and pdftex, and I don't think that would have happened if there were patents involved. I'm guessing that Adobe's threat of a lawsuit against MS is based purely on MS's status as a monopolist. Being a monopolist isn't illegal, but abusing monopoly power is, and it sounds like Adobe thinks it has a valid case that including this functionality in office would be such an abuse.-- 00:18, 5 June 2006 (UTC)
If anyone is interested, the PDF specification is available at The section "Intellectual Property" on page 7 gives the copyright/patent terms. As far as I can see, you can do anything with PDF files as long as you respect access permissions in them, and give credit if you use the list of operators (which I suppose you must). It explicitly doesn't give you rights to use patents. But if it didn't mention any patents, you still wouldn't have any rights to use them AFAIK. It seems that whenever someone discovers a patent that applies to a part of the PDF specification, Adobe license the patent for users of the specification - see, for example. Nick8325 01:21, 5 June 2006 (UTC)
Though it does say that in the same introduction. Perhaps some word re-ordering could help. Notinasnaid 09:33, 30 May 2006 (UTC)

Seems Adobe is taking Microsoft to court to prevent them from putting PDF support into Microsoft Word 2007. [1] If PDF is an open standard, how can they prevent other vendors from making software that can create PDF files? --Thoric 21:34, 2 June 2006 (UTC)

They are trying to prevent Microsoft from including PDF support into Office 2007 for free; instead Microsoft should sell that as an add-on. It has nothing to do with PDF being free.--Oneiros 22:03, 2 June 2006 (UTC)
If PDF is "free" how can they prevent Microsoft from including support for it? BTW, Office 2007 is not free. --Thoric 16:07, 5 June 2006 (UTC)
An interesting story is emerging, but it seems that journalists don't know what they are talking about. That story says "Microsoft would need Adobe's cooperation to include PDF-creation capabilities in Office 2007" which is nonsense. I think Microsoft have enough programmers to do that, and Adobe specifically grant the rights to do it. This story on CNet [2] sounds like it has more of a handle on things "Adobe has threatened to file an antitrust complaint against Microsoft". That isn't exactly legal action, but it's close enough. Of course, things get messy: "However, the parties remain in licensing negotiations over Microsoft using Adobe Reader to view PDFs in Vista" (same story). Notinasnaid 22:05, 2 June 2006 (UTC)
It will be an anti-competive thing, and governed by national (or EU) legislation - if Microsoft bundle PDF creation software with thier operating system, it's considered an abuse of their market position, and would screw Adobe (and other 3rd party companies) who want to sell PDF creating software to the public.
Also, Microsoft might be intending to screw the spec. Remember what they tried to do with Java? Nil Einne 08:49, 18 November 2006 (UTC)


Is it possible to add text to a regular PDF File? If so, how? Jbm867 07:12, 13 June 2006 (UTC)

PDF files are not editable unless you use one of the special PDF editing programs that supposedly decompile PDFs back into a word processing document such as an RTF, Microsoft Word .DOC or Word Perfect .WPD file. I have never used any of these PDF decompilers — I've simply seen them in stores — so I don't know how well they work. Paul Robinson (Rfc1394) 18:01, 14 June 2006 (UTC)
Adobe Acrobat has some very limited tools for this. They add text; but that's all. Don't expect other text to move around to make room. Notinasnaid 20:33, 14 June 2006 (UTC)
This is a bit of an oversimplification. Acrobat can edit some aspects of a file, and can edit text line by line. Other tools such as Enfocus Pitstop Professional provide more advanced tools, such as text editing by paragraph. Some applications such as Adobe Illustrator can use PDF as a native format.Elliot100 16:06, 7 December 2006 (UTC)
Not just an oversimplification, but false. It is possible to add text to a PDF file with at least two applications, Adobe Acrobat and Nitro PDF. There are probably others. And the Pitstop plugin to Acrobat adds more powerful editing capabilities than Acrobat by itself. Generally it is meaningless to use the term "editable" in respect to a file format. All file formats are editable. The interesting question is what kinds of edits a format makes easy or hard. The design of the PDF format makes editing of text (especially with reflow and layout adjustments) technically more difficult than it is in, say HTML. But it is not impossible by a long shot. The technical difficulty of doing it well is reflected in the expense of the software that does it. Mrhsj 16:21, 7 December 2006 (UTC)

Cleanup tag

The cleanup tag was added on December 17, 2005 by Pandion auk but the user failed to explain on this talk page why he added the tag (perhaps too many external links?). Does anyone object to the removal of the tag and if so, why? RedWolf 22:07, 15 June 2006 (UTC)

Well, it could be something to do with the way the article is rambling, unstructured, poorly researched, and poorly written. Fix the article before removing the tag, please. If you want specifics about what's wrong, get it peer reviewed. 10:21, 23 June 2006 (UTC)
I agree with all these points. It's really a very poor article, even though it is full of facts, many of which are relevant but disorganised, but it is missing many relevant facts, and lacking sources. I looked into improving it, and concluded the only way to do it was a complete rewrite that I don't have time for (and which would doubtless be reverted if I tried). Notinasnaid 10:34, 23 June 2006 (UTC)

Phoning home

Wow, this "phoning home" business is a surprise to me. Presumably it depends on the viewing software to decide whether or not to obey the phone-home instructions. I'm glad I don't use Acrobat Reader! Can some PDF expert confirm that phoning-home is indeed application-dependent, and let us know what viewers actually do phone home? 09:42, 13 July 2006 (UTC)

What is there to be concerned about? Every web page you visit "phones home" in exactly the same way, and nobody seems to get too excited about that. Notinasnaid 09:43, 13 July 2006 (UTC)
Sure, that's the nature of the web; communicating with a web-server is an essential part of the process. But PDF's are typically viewed offline; the last thing you expect them to do is to report behind your back the fact that you've opened a file which is located on your own computer. It's nobody else's business, and it's totally unnecessary. If all Microsoft Office files secretly phoned home to Microsoft Corp. every time they were opened, would privacy advocates get excited? Damn right they would, and rightly so! 21:50, 13 July 2006 (UTC)
Well, I can't get excited about it, but Adobe seemed to have taken it seriously, hence the latest Adobe Reader prompts before a PDF can submit itself in this way. (7.0.5 I think). Notinasnaid 18:19, 16 July 2006 (UTC)

Another good reason to use a tool like Zone Alarm.-- 16:32, 12 February 2007 (UTC)

PDF on the Web

  • "the inflexibility of PDF rendering makes it difficult to read on screen: it does not adapt to the window size"

That's not true is it? One thing it DOES do is adapt to the window size. 13:48, 3 November 2006 (UTC)

Not really. PDF's have a fixed format and page size. All you can really do is zoom in and out. As such they're only look good and are easy to read and navigate on certain sized screens. Alternatively think of making a window that's say 1/4 of your normal screen size. I'm lazy to explain, but think of trying to read a normal pdf on a PDA or mobile phone. Properly designed webpages and other documents without a fixed format however can adjust to the window size. The font size, layour etc can change. Nil Einne 08:46, 18 November 2006 (UTC)

Looks like someone else has removed this. Daveches 20:40, 14 January 2007 (UTC)

When exactly "died out" the DjVu format ???

There is a big mistake at the hystory section. I don't really understand how PDF and DjVu file formats could compete in the "early 1990s" when DjVu was invented in 1996 and I don't think that DjVu "died out". At least, this is what comes out from the text. Maybe the pharagraps should be modified like: Additionally, during the years, the PDF should compete with other formats like Envoy, Common Ground Digital Paper, DjVu and even Adobe's own PostScript format (.ps). Adobe succesfully supported PDF through its slow multi-year ramp-up. One policy of the firm was to distribute the Acrobat Reader (now Adobe Reader) program at no cost. Some of the competing formats eventually died out, and PDF became a well-accepted standard.

Èʍ≈ 14:03, 6 November 2006 (UTC)

I agree. PDF was already prevalent before DjVu. I shall edit it. Someone change it if it is crap.

Searchable Image Exact

Could anyone update the page with the latest Searchable Image technology from Adobe?

"Searchable image exact" is not new (it's been possible since PDF 1.0 and used since Acrobat 3), and is not a type of PDF, so it does not belong in the article. It is an option in Acrobat, that's all. There are many ways to make a PDF, and this is one of them. This common fallacy is covered in commentary on the second external link. Notinasnaid 08:08, 9 November 2006 (UTC)


PDF is a file format instead of a programming language and for that reason it doesn't need to be interpreted.

Of course it needs to be interpreted: it's not compiled and then executed. I would fix this, but I'm not sure what it's trying to say; any ideas? Marnanel

I think it's trying to say that the process of handling a PDF is not like the process of handling a PostScript file, which is the execution of a program. Rather, the PDF format contains descriptions: it isn't procedural. Notinasnaid 17:57, 29 November 2006 (UTC) seems like a website that provides a useful service. Maybe it should be included in this article?

Why? What criterion from Wikipedia:External_Links does it satisfy? Being a "useful service" doesn't appear to be on any list there. Mrhsj 04:01, 1 December 2006 (UTC)

Removed criticism

I removed (twice) the following text "On some systems, a PDF file can cause a crash or be inaccessible. In addition, large PDF files can take very long to download off the Internet."

1. This is just vague criticism, and some specific citation is needed from a reliable source (not a blog, for instance) that says this. 2. This uses weasel words which are not suitable for Wikipedia articles; what would "be inaccessible" mean for a file format? What are these "some" systems? 3. Crashes are a matter of software NOT file formats; this confuses the software you are using to view PDF, with PDF the file format. 4. Large files of any kind can take a long time to download; this criticism applies to any large file, not to PDF files specifically. Wikipedia is not a place to vent your understandable frustration, in my opnion. Notinasnaid 10:11, 1 December 2006 (UTC)

Correction: another editor got in ahead of me for the second removal. Notinasnaid 10:12, 1 December 2006 (UTC)
PDF is bulkware, so that's why even 10 page files take too long to load for my taste. You see, I HATE how Wikipedia has to be a smart ass with everything like this. Why can't we accept "common knowledge restricted to certain demographics"? Jessus.. stop with all the "weasel words" already. It's a stupid buzzword/"weasel word" itself, ironically. "Some systems" is WELL ENOUGH for any user in any writing in any report in any document et cetera. -- 00:34, 28 December 2006 (UTC)
The size of a PDF depends on how you make it. (That should perhaps go into the article somewhere.) You can easily get a huge file for a 10 page document if the file contains high resolution images of the text. However, you can also slim it down, and if the text is stored as text alone, a PDF file is almost always smaller than a MS Word document of the same quality. Mlewan 06:48, 28 December 2006 (UTC)