Since the International Organization for Standardization (ISO) published the first portable document format/archive (PDF/A) standard in 2005, PDF/A has been heralded by recorded information management professionals and archivists as a mechanism for the secure, long-term preservation of electronic documents. PDF/A, a subset of the ubiquitous PDF format, doesn’t depend on external programs or information to be displayed. All information in a PDF/A file is entirely self-contained with the elimination of standard PDF features such as font linking which are not conducive to long-term archiving.
In the continued development of the standard, the ISO recently published ISO 19005-3:2012 Document management — Electronic document file format for long-term preservation — Part 3: Use of ISO 32000-1 with support for embedded files (PDF/A-3). The standard is available for purchase from the ISO.
According to the ISO, PDF/A-3 “specifies the use of the Portable Document Format (PDF) 1.7, as formalized in ISO 32000-1, for preserving the static visual representation of page-based electronic documents over time in addition to allowing any type of other content to be included as an embedded file or attachment.”
What this means is that a complete archived object in PDF/A may now include embedded files or attachments in formats such as XML, CAD, wordprocessing documents, imaging, etc. This is a major change from PDF/A-2 which allows embedded files, but only of the PDF/A variety.