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Open standards
With respect to websites that focus on information exchangeability, it is advisable to make optimal use of open standards, since this improves communication between the sender and recipient of information.
The importance of standards in relation to exchangeability
The importance of standards in communicating or exchanging information can best be explained by means of an example: language. A language is a set of rules for speech and writing (a standard) that ensures communication, provided that the ‘sender’ and the ‘receiver’ speak the same language. If two parties use the same standard, communication is made easier. The exchange of information is effective. Naturally, if the sender and the receiver each speak different languages, communication is more difficult.
On websites, information is transferred through digital files: as web pages (HTML), images (PNG, JPEG, GIF) or text documents (ASCII, PDF), to name just a few examples. Sender and receiver must be able to create and ‘read’ these file formats.
Much-used file formats become de facto standards over time. We can conclude that it is important to use file formats that can be used by most people - the most universal standards. Web developers must however use open standards as often as possible.
What are open standards and why are they important?
An open standard is a standard that is not owned by anyone and can be used by everyone. For example, nobody owns HTML or CSS. This is the opposite of proprietary (closed) standards, such as Microsoft's Word format.
The OSSOS programme defines open standards as follows.
'Open' ICT standards for interoperability of information systems (or the capacity to exchange data between ICT systems). Standards can be 'open' or 'closed'. An 'open standard' is understood to be a standard that complies with the following requirements:
- The standards are adopted on the basis of an open decision-making procedure (consensus or majority decision, et cetera).
- The standard is controlled by a not-for-profit organisation with a completely free access policy.
- The standards have been published.
- The costs for the use of the standard are low and do not impede access to the standard. Any intellectual property rights underlying an open standard are made available royalty-free.
- There are no restrictive conditions on the re-use of a standard.
One example of an open standard is the XML standard. XML is short for Extensible Markup Language and is administered by the W3C. This non-profit organisation administers most internet standards, together with IETF. XML specifications can be downloaded from the W3C website free of charge. There are also forums in which the new version of XML is discussed. Any organisation can become a member of W3C for a small fee. No restrictions are placed on the use of XML.
What are open standards?, OSOSS
Anyone can read and implement open standards. The information needed to do this is often available on the Web. There are even more benefits, however.
- Open standards ensure an honest marketplace and do not create dependence on a specific company or organisation.
- Open standards can be implemented free of charge.
- The organisations that apply the standards do not expres supplier preferences.
Recommended file formats
Using open standards for websites is important for the reasons indicated above. For practical reasons, however, it is conceivable that information is offered through frequently-used closed standards (such as Word and Excel).
In the event that important information is provided through a closed standard, the same information should also be provided through an open standard.
Guideline R-pd.5.1
The information on an HTML page (open standard), may also be available in Word (closed standard). A number of closed standards are given below, with open standards as alternatives.
| Type of file | Non-open standard | Open standard |
|---|---|---|
| Text | Microsoft Word; WordPerfect | HTML; plain text; PDF/A-1a |
| Image | GIF; BMP | PNG; JPEG |
| Video | RealVideo; WMV | Theora; H.264/AVC/MPEG-4 part 10 |
Between open and closed standards
When publishing information or creating services on the Internet, open standards should be used to ensure accessibility and durability. This does not automatically mean that non-open standards are inaccessible or of poor sustainability.
File formats like RTF, GIF and WMV do not conform to all aspects of the OSOSS and IDABC definitions of open standards. The specifications of these file formats are freely available, but not freely licensed. GIF uses a compression algorithm that was patented until 2004, the RTF and WMV specifications are the property of a commercial company (Microsoft).
PDF is often assumed to be a closed standard, owned by Adobe. This not absolutely true: since October 2005 the PDF/A specification is official ISO. This format is primarily developed for archiving purposes. One part of it, PDF/A-1a, is suitable for publication of accessible content on the web. A specification for accessibility, PDF/UA (Universal Access) is being developed as an open standard, but has not yet been released.
In September 2007, a position paper on the use of PDF in relation to the Web Guidelines was published (currently available in Dutch only).
GIF, non-open PDF and RTF are popular formats that are supported by a wide variety of computer operating systems. User programmes can be downloaded free of charge, but these formats do not meet all the requirements of open standards. Still, when it comes to sustainability and accessibility, these formats are to be preferred to closed office standards. Publishing GIF, non-open PDF en RTF is only acceptable if there are practical impediments to the use of available open alternatives. The precondition is still that all content must be accessible to every user.
The use of GIF, PDF and RTF as original source formats is discouraged. Instead we recommend generating these files from a genuinely open resource, for example XML. Thus, the sustainability of the stored content and accessibility of the presented content can be optimally warranted.
Links and references:
- GIF 89a specification. (Alternative link)
- RTF specification (various versions)
- PDF specification 1.3, 1.4, 1.5 and 1.6
- Position paper on the use of PDF in relation to the Web Guidelines (Dutch only; PDF document, 212 Kb)
