Portable Document Format. A format for document exchange, no matter the software, hardware or operating system being used.
Actually, scratch that software bit. These days Adobe LiveCycle seems to be producing an awful lot of PDF files which can only be opened in Adobe products. Oh, and you better scratch that hardware and operating system bit too, because the latest versions of Adobe Reader and Adobe Acrobat aren't available on all devices and operating systems.
Portable. A PDF that is created in an Adobe product and can only be opened in an Adobe product is not portable. You may have come across this delightful message before:
To view the full contents of this document, you need a later version of the PDF viewer. You can upgrade to the latest version of Adobe Reader from www.adobe.com/products/acrobat/readstep2.html For further support, go to www.adobe.com/support/products/acrreader.html
That's an interesting message. Instead of showing me the content of the PDF, I'm shown a message that tells me I need later version of the “PDF viewer” and then it directs me to download Adobe Reader. But I didn’t open this PDF in Adobe Reader, I used an alternative application, so why am I being instructed to download Adobe Reader in order to view this Portable Document Format file?
Is Adobe creating PDF files that can only be opened in Adobe products? Yes, it appears they are and have been doing so for a number of years.
Adobe will tell you that what they're doing is fully compliant with ISO 32000-1, that the ISO standard fully documents both the encryption algorithms and includes XFA as a normative reference, which is true.
That's not really the issue. The issue is that Adobe is preventing any PDF viewer from opening these PDF files unless it is version 8 or newer of Adobe Reader or Adobe Acrobat.
Now perhaps the ISO standard doesn’t prohibit this sort of behavior, but I think it's fair to say that it goes against the grain of what PDF is all about. It knee-caps the concept of a portable document without so much as a "how do you do" or an explanation of why and makes a mockery of PDFs original intent.
PDF might be an ISO standard these days, giving Adobe some cover to make more commercially orientated decisions, but Adobe is still the standard-bearer of PDF and should not be in the business of creating crippled-PDFs.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.