PDF/A is the ISO standard for archiving electronic documents using the PDF format. The first part, PDF/A-1, was published on October 1, 2005. The second and third parts, PDF/A-2 (2011) and PDF/A-3 (2012), enhance PDF/A with support for additional features in the PDF format, including options for combining several PDF/A files into one PDF/A collection or embedding the PDFs source files or other data, support for transparency, and much more.
The creation of the multi-part PDF/A standard required many years of cooperation between international delegates from software developers, industry associations and government agencies.
ISO 19005 defines a file format based on PDF, known as PDF/A, which provides a mechanism for displaying electronic documents in such a way that the visual image is maintained over time, irrespective of the tools and systems used for their production, storage and reproduction.
PDF/A does not define an archiving strategy; the standard simply details technical requirements for PDF electronic documents to ensure reliability decades or even centuries after the files creation.
Since 2005 PDF/A has become well-established as the preferred format for archiving electronic documents. The PDF format, itself standardized in 2008 as ISO 32000-1, is used around the world in public and private sectors and, after HTML, remains the most popular format online. PDF will continue to be employed as a robust and flexible document format in a variety of areas for the foreseeable future.
PDF/A ensures reliable access to PDF documents, making PDF ideal for long-term archiving.