PDF/A A standard for document archiving. Dipl. Inf. Reinhold Müller-Meernach. Dr. Uwe Wächter. SEAL Systems info@sealsystems.com

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1 PDF/A A standard for document archiving Dipl. Inf. Reinhold Müller-Meernach Röttenbach Dr. Uwe Wächter Roßdorf No. 2/2006 SEAL Systems info@sealsystems.com

2 PDF/A A standard for document archiving Dipl. Inf. Reinhold Müller-Meernach Röttenbach Dr. Uwe Wächter Roßdorf The»leader of the pack«tiff/g4 has got competition. With PDF/A, a new standard for long-term archiving of electronic documents has now been defined. Checks on existing document archives show that a large amount of the PDF files archived there don t even meet the minimum requirements of the new standard. But this is no longer a reason to panic.

3 Paper archives have been and are being replaced by digital storage. The number of electronically created documents is growing constantly. For long-term archiving of these documents, standards are beneficial if the well-defined reproducibility and distribution is to be supported over a long period of time. The monochrome grid format TIFF/G4 has been the de facto standard for more than ten years. For text-laden documents (such as those from Office applications), the Portable Document Format, PDF for short, from Adobe has become established as an application-neutral exchange format. With PDF/A, there is now a standard, that establishes a part of the PDF specification to make PDF files particularly suitable for archiving. The ISO Norm is based on the»pdf Reference 1.4«from Adobe. It makes PDF 1.4 more precise and defines whether its properties are obligatory, re- References to external sources, such as further files, images, websites or external fonts contradict the PDF/A norm. An especially important characteristic of PDF/A is the embedding of fonts. Only this can ensure that a document can be printed in exactly the same way after many years, without having to use font definitions on a computer or printer. PDF can also demonstrate its advantage over TIFF G4 through its colour displays. However, this only conforms to standards if the Fig. 1: Investigations show that almost no PDF files in existing archives conform to PDF/A. (Fig.: Seal Systems AG, Röttenbach) of this are the effects of transparency, colour mixing and background stamping. These characteristics can not be represented 1:1 with many PDF generating processes. Therefore, with PDF/A, this must be avoided. Secure archiving in line with the norm Secure archiving in line with the norm means that the saved files can then still be used if the administration system corrupts. There- Fig. 2: With test and correction procedures for PDF/A, data stocks can be viewed and modified as the case may need. (Fig.: Seal Systems AG, Röttenbach) commended, limited or prohibited. This makes it possible to differentiate two levels of PDF/A: a (PDF/A- 1a) and b (PDF/A-1b). Level B is important for archiving Level B deals mainly with the preservation of the external appearance over long periods of time. To do this, it is necessary that all the information needed for the reproduction is contained in the file itself. For example, this concerns all texts, graphics, images, fonts and colour information. PDF file can also be printed instantly on all colour printers. To do this, colour definitions unrelated to the equipment are saved in the file, which are only converted when printing. Simple and safe reproduction can be prevented through protective mechanism, compressions and encodings. Therefore, these techniques are also prohibited for PDF/A conforming files. Frequently, image overlapping in certain applications can be specifically used to elicit certain effects for the observer. Examples fore, PDF/A-conforming files must operate a clause on metadata. The Portable Document Format makes it possible to save graphic displays in different representations simultaneously. This means an improved display on different screens (PC or Handheld or PDA) or a user orientation (German or English) is possible. However, as reproduction is unclear with this method, this function contradicts ISO When using level A, such characteristics are additionally standardised using level B, which define the

4 properties for content, structure and semantics. This means there is the opportunity to be able to re-extract parts or information from the PDF documents at a later point in time. Furthermore, this level explains how a Unicode font must be dealt with. Work is already being carried out on the expansion of this norm, which is named and is based on»adobe PDF Reference 1.6«. PDF/A level A covers the complete norm Every international norm is a compromise between the interest groups concerned and their requirements, which can be contradicting in parts. Existing procedures and local regulations should be taken into account. On the other hand, new technical possibilities also shouldn t be ruled out. Maximum specification of all details can lead to unusability in Fig. 3: Test logs provide users and IT managers with information about the quality of the data stock. (Fig.: Seal Systems AG, Röttenbach) operational practice. Therefore, it must be checked whether company standards can also be defined taking into account practicability and compatibility with existing procedures. This takes over definitions from the ISO norm, combining comprehensible instructions for action which can be used by all company members. Define minimum standards The past has shown that even individual industries can agree on a standardised comprehension and procedure. If a company decides on PDF as a reliable document format for long-term archiving, then this is the next logical question: is every PDF allowed or must it satisfy certain minimum requirements? When answering this question and defining the minimum standards, the ISO norm for PDF/A can help. When this question is answered then the next steps can be taken. It must be clarified which procedures guarantee that these minimum requirements are complied with. In addition, it must be decided how to proceed with any old stock. And finally, it must be specified who is responsible for inspection and compliance of these processes. In the meantime, there are now countless software tools for creating PDF files. The most wellknown is Acrobat from Adobe. As well as many converting applications from third-party suppliers, there are a number of applications that make it possible to directly export PDFs. In the future, this should also be possible for the Office products from Microsoft. However, investigations show that some PDFs created in this way do not even meet the standard specification, so definitely fall short of the stricter ISO In a very small number of cases, PDF files are created solely within the company with an inspected tool. PDF is an exchange format meaning the probability that considerable data stocks stem from other, uncheckable sources is high. Business partners, the internet and s are examples of this. For these reasons, it makes more sense for the standard to be inspected by the responsible body within the archiving organisation. Nowadays, there are test programs, with which PDF files can be inspected for configurable ISO and company standard compatibility. The result of an inspection is always a confirmation of Fig 4: PDF/A inspections can be integrated into existing Document Management Systems (DMS) and Product Data Management Systems. (Fig.: Seal Systems AG, Röttenbach)

5 conformity or a rejection. In the latter case, a qualified analysis should take place so that the creator can be given targeted instructions for use. However, an alternative to rejection can also be the automated correction of a PDF file to norm conformity. Frequently observed incompatibilities, such as missing font embedding, can be corrected as a result with the minimum of steps can be derived from this. A part of the data can be corrected, another part not. PDF/A an archiving format with a future If the sources are known, it can be possible to make a new normconforming version available. First experiences in reference supplies from industrial customers have Fig 5: The diagram shows the integration of the PDF/A methods into the SAP document management system. (Fig.: Seal Systems AG, Röttenbach) becoming more powerful and extensive with every new version. 3D visualisations, form processing, digital signatures, change management and pre-print inspection are only parts of the PDF application spectrum. The use as an extensively simple exchange format suggests itself for use as an archiving format. The technical requirements here are less but the legal ones are higher. With PDF/A, a norm has now been passed, with which risks and future expense for long-term archiving can be minimised. There are tools to generate, inspect and adjust PDF/A files. As a result, the new standard will rapidly be established as practical alternative. effort. To safeguard processes, the question of the time of a conformity inspection is decisive. The first and best time is definitely the generation process. For unknown documents or nonsecured generation processes, a simple checking procedure is supplied on the desktop. Both methods make it easier for the parties concerned to carry out an inspection but do not force them to do so. Therefore, it is recommended that the manufacturer and operator of Document Management Systems (DMS), *Enterprise Content Management Systems (ECM) and archiving solutions provide a suitable interface, through which test methods can be integrated. If this interface is then run by all archiving and converting processes, the PDF/A inspection is obligatory. Even for existing PDF archives, a one-off or regular inspection is recommended. A first run provides information about the quality of the data stock. Then subsequent shown that almost no PDF file met the PDF/A-1b definition. The most frequent errors are (in this order) missing metadata, no font embedding, colour management and protection mechanisms. However, any weaknesses can be automatically corrected through suitable tools. The Portable Document Format is Fig. 6: The data format PDF/A is classed as a norm, with which both the risks and predominantly the expense of long-term archiving can be minimised.