This white paper uses a variety of trusted sources to explain the significance of new Portable Document Formats (PDFs).

“Traditional archiving methods such as paper and microfilm guarantee reproducibility but have been superseded by new technologies.  The popularity of PDF (over TIFF) grew for a variety of reasons but the format’s proprietary nature meant that reproducibility over years could not be guaranteed.  Hence the need for a standard was felt in the early 2000.

An initiative to create a PDF standard format was launched in May 2002 in the US by AIIM, NPES and the US Courts.  Numerous organisations, users and suppliers were subsequently involved in the process.

On September 28, 2005, ISO announced PDF/A-1 as the global electronic archiving standard for long-term preservation. (ISO 19005-1:2005 DM e-file for long-term access)

The PDF/A-1 standard identifies with PDF (v1.4 or later) and provides a ‘profile’ that ensures reproducibly in years to come.

The key element to this standard is the 100% self containment factor.

PDF/A file is not permitted to be reliant on information from external sources.”

– Information provided by eDocuMAN 

Why PDF/A?

“The feature-rich nature of PDF can create difficulties in preserving information over the long term, and some useful features of the PDF file format are incompatible with the demands of long-term preservation.

For example, PDF documents are not necessarily self-contained, drawing on system fonts and other content stored externally to the original file. As time passes, and especially as technology changes, these external connections can be broken, and the dependencies cause information to be lost. Additionally, because of the lack of standardisation among the many PDF development tools on the market, there is inconsistency in the implementation of the file format.

This lack of standardisation could be chaotic for the information managers of the future, especially as it would be difficult (if not impossible) for them to “get under the hood” of the PDF files unless a format specification were put in place that specifically addressed long-term preservation needs.

All over the world, tremendous quantities of valuable information are currently being created and saved as PDF, and a specification solution is needed to ensure that digital PDF documents can be rendered, readable, and accessible for the long-term. PDF/A is designed to be that specification.”

 What is the difference between PDF and PDF/A?

“The PDF/A-1 (ISO 19005-1:2005) standard is based on Adobe’s PDF Reference 1.4, and specifies how to use a subset of PDF components to develop software that creates, renders and otherwise processes a flavour of PDF that is more suitable for archival preservation than traditional PDF. PDF/A-1 aims to preserve the static visual appearance of electronic documents over time and also aims to support future access and future migration needs by providing frameworks for: 1) embedding metadata about electronic documents, and 2) defining the logical structure and semantic properties of electronic documents. The result is a file format, based on PDF 1.4 that is more suitable for long term preservation. PDF/A-1 files will be more self-contained, self-describing and more device-independent than traditional PDF 1.4 files.”

Does PDF/A-1 support digital signatures?

“Yes, PDF/A-1 allows the use of digital signatures embedded in PDF as defined in the PDF Reference Manual. Because PDF digital signatures include a visual appearance, the appearance must conform to all the requirements of PDF/A-1 including font embedding and use of device independent colour. Not all commercial digital signature tools follow these requirements.”

Information provided by ISO 19005-1:2005 PDF/A-1 Date July 10, 2006 Frequently Asked Questions (FAQs)

“By itself, PDF/A does not necessarily ensure that the visual appearance of the content accurately reflects any original source material used to create the conforming file; e.g. the process used to create a conforming file might substitute fonts, reflow text, down sample images or use lossy compression. Organisations that need to ensure that a conforming file is an accurate representation of original source material may need to impose additional requirements on the processes that generate the conforming file beyond those imposed by this part of ISO 19005. In addition, it is important for those organisations to implement policies and practices regarding the inspection of conforming files for correct visual appearance.”

ISO 19005-1:2005 (E)

In Summary

For document conversion solutions to be of value to our clients it needs to address the concerns of;

  1. Are the images of archive quality?
  2. Are the images a true reproduction of the original document?
  3. I need my staff to have access to the electronic documents. How can I ensure they have not been altered?
  4. I need to be confident if there is a dispute I can rely on my documents having a high degree of credibility.