Electronic document file format for long-term preservation. PDF/A-1, PDF for Long-term Preservation, Use of PDF 1.4. Adobe has a number of patents covering technology that is disclosed in the Portable Document Format (PDF) Specification, version 1.3 and later, and hence in the ISO 19005-1 specification by reference.
As an ISO standard, the compliance of ISO 19005-1 with the ISO/IEC/ITU common patent policy has been vetted. A summary of relevant information on the Adobe Web site in September 2010 (see follows. The PDF/A Competence Center [pdfa.org]