OK – I know that PDFs are a file format used for portability, and that the format was developed originally by Adobe in the early 1990’s.
I was also aware that PDFs are pretty damn popular. And useful. We use them in our Regulated Document Management System to ensure that the documents are “locked”, and that the content cannot be easily modified.
What I did not know was that the PDF format was released as an open format in July of 2008, and was published by the International Organization of Standardization as ISO 32000-1:2008. Here is a definition of the standard from Wikipedia:
ISO 32000-1:2008 specifies a digital form for representing electronic documents to enable users to exchange and view electronic documents independent of the environment in which they were created or the environment in which they are viewed or printed. It is intended for the developer of software that creates PDF files (conforming writers), software that reads existing PDF files and interprets their contents for display and interaction (conforming readers) and PDF products that read and/or write PDF files for a variety of other purposes (conforming products).
I was also aware that there were various “flavors” of the PDF format. I just never really understood what they were.
The following is a brief description of the various kinds:
PDF/Archive, or PDF/A. This is the electronic document file format for long-term preservation. Documents stored in PDF/A will always be able to be viewed by future versions of the Acrobat Reader. To achieve this a PDF/A document needs to be 100% self-contained. It cannot rely on information from external sources.
PDF/X. This is a PDF format that is designed to enable reliable transmission of files from one print site to another. It has several printing-related requirements that are not found in standard PDF files. These include the requirement that all fonts are embedded and that the color of all objects be expressed in CMYK or spot colors, prepared for the intended printing conditions. A later version of the format allowed a bit more flexibility with regards color.
PDF/E. This PDF format describes how PDFs should be used for the transfer of engineering and technical documentation. A white paper from Adobe describes how this is done. Using version 1.6 of PD, it includes settings to ensure low storage and transfer costs (vs. paper), a trustworthy exchange across multiple applications and platforms, and that the document is self-contained.
PDF/Healthcare or PDF/H. In 2008 AIIM published version 1 of A “Best Practices Guide”describing attributes of the Portable Document Format (PDF) to facilitate the capture, exchange, preservation and protection of healthcare information. This is intended to develop a secure, electronic container that can store and transmit relevant healthcare information, including: personal documents, clinical notes, lab reports, electronic forms, scanned images, photographs, digital X-rays, and ECGs.