PDFA-1b format is a conformance option of the PDF/A format, which is used for the long-term archiving of electronic documents.
PDF/A is defined in ISO 19005-1:2005 as follows:
"...PDF/A is in fact a subset of PDF, obtained by leaving out PDF features not suited to long-term archiving. In addition, the Standard places requirements on software products that read PDF/A files. A "conforming reader" must follow certain rules including: following color management guidelines; using embedded fonts for rendering; making annotation content available to users; etc..
The Standard does not define an archiving strategy, or the goals of an archiving system, it identifies a "profile" for electronic documents that ensures the documents can be reproduced the exact same way in years to come. A key element to this reproducibility is the requirement for PDF/A documents to be 100 % self-contained. All of the information necessary for displaying the document in the same manner every time is embedded in the file. This includes, but is not limited to: all content (text, raster images and vector graphics); fonts; color information; etc.. A PDF/A document is not permitted to be reliant on information from external sources.
PDF/A-1b has the objective of ensuring reliable reproduction of the visual appearance of the document. PDF/A-1a includes all the requirements of PDF/A-1b and additionally requires that document structure be included (also known as being "tagged"), with the objective of ensuring that document content can be searched and re-purposed...".
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