Accessible internet

from Wikipedia, the free encyclopedia

Barrier-free Internet are web offers that can be used by all users without restrictions ( barrier-free ) regardless of their limitations or technical possibilities . The use of the term Internet is a colloquial equation of the term “Internet” with the World Wide Web .


Accessibility includes people with and without disabilities as well as users with technical ( text browser or PDA ) or age-related restrictions ( poor eyesight ) as well as web crawlers with which search engines record the content of a page.

From a statistical point of view, people with disabilities are on the Internet more often than average and are dependent on special processing of the web offers that go beyond the usual presentation ( rendering on the screen, audio data conversion ) so that they can participate as fully as possible in the digital world . Blind and visually impaired users can have websites read aloud using software or output in Braille ; deaf or hard of hearing people whose first language is sign language need special forms of presentation on the Internet that are tailored to their needs.

In addition to taking into account the concerns of disabled people, “barrier-free” ( disabled-friendly denotes only one aspect) that in general no barriers should be placed in the way. Even non-disabled users should not be required to use exactly the same hardware and software configuration as the author of the offer when accessing Internet offers (technical accessibility) . Beyond accessibility ( Accessibility ) is about the platform independence  - an Internet service to both screen in any format and with PDA , cell phone can still be used. It should work independently of the operating system and software used , provided they work in accordance with the standards.

At least as important as technical access conditions is that the content is presented clearly and in easily understandable language . Accessibility includes: not making excessive demands on education , training and intellectual level , but on the subject . This context is particularly binding for the public law web offers, in order to realize the demands for equality also for linguistically handicapped people in a country ( mother tongue deviating from the majority ), but also includes the problems of older people who are not familiar with the possibilities and methods modern communication grew up, and socially disadvantaged classes.

Concept history

The term accessibility was originally used in the construction industry and describes buildings that are accessible to wheelchair users without any obstacles. In the field of information technology, the term was first used in 1993 by the Dortmund Center for Disability and Studies (DoBuS) as a metaphor for user interfaces of software; It coined the catchy term "barrier-free user interface", which has become generally accepted in the German-speaking area. In the association, the demand for the barrier-free Internet was made public for the first time. For this, the term originally used in construction was transferred to the then rapidly developing area of ​​the Internet. The main demand of the association was that all information on the Internet should be made available to all users regardless of the application of certain programs.

Internet techniques that are barriers

With the help of various devices, it is also possible for the severely disabled to use computers.

The modern technologies of information processing and web design offer an abundance of different technologies to display content that in the last ten years has increasingly gone beyond the pure preparation of text ( plain text ) . Due to the resources, the aids that are necessary for the display can often not be adequately updated when it comes to marginalized groups . Such measures on the part of the providers of websites, but also the providers of infrastructure and operating software, are called exclusionary mechanisms .

  • Well-structured text can be read by blind people using a Braille display with the appropriate software ( screen reader ). Sighted people also benefit from searching and editing texts if they are well structured. Images - or text that is contained in images - are inaccessible to the blind and should therefore be supplemented with alternative text. Frames are not an obstacle if they support the structure, for example separating navigation and content.
  • Visually impaired need scalability of the font in the browser, in order to adapt the font size to their visual performance.
  • People with low vision may need high contrast and clear fonts, as well as control over the color of the font and background.
  • For people with color ametropia, for example as a result of a red-green visual impairment , it is problematic if information about color alone is conveyed. Therefore, statements such as "Press the red button" should be avoided.
  • Visually impaired people are at a disadvantage when it comes to navigation that consists of images, Java applets or Flash objects.
  • Flashing or animated texts represent a barrier for people with a visual impairment and / or a cognitive disability, as they distract from the actual content.
  • People with spasticity or other motor disorders who cannot operate a mouse must navigate with the keyboard . You move (usually with the tab key) through the links, form elements, and other active objects on the page. So that a website can be operated easily with the keyboard, it is important that the elements are controlled in a meaningful order and that it is always clear which element is currently in focus.
  • Deaf people have often learned sign language as their first language. For them, written language is a foreign language and usually difficult to understand. Acoustic content cannot be recorded by deaf people. They should therefore be replaced by or accompanied by visually perceptible content. Websites that are presented in sign language are barrier-free for them.
  • People with cognitive disabilities usually have problems understanding long and awkwardly worded texts with difficult nested sentences and foreign words as well as complex navigation. That is why it makes sense to write websites in so-called " easy language " or offer translations in "easy language".
  • Many of the content management systems (CMS) currently in use generate pages that are difficult to access for disabled people. Only very few systems or processes support the authors with barrier-free input options.
  • Failure to comply with technical standards (incorrect coding of umlauts, invalid HTML) creates websites that are only displayed by certain browsers as requested by the author.
  • Dynamically processed and interactively accessible information represents an information-sociological innovation to a similar extent as the Internet itself. However, the risks of exclusionary mechanisms increase according to the variety of possibilities. With the spread of Ajax, there is a risk that accessibility will fall behind even faster.
  • To touch screens (especially mobile phones) is usually no mouse or other input device available with the exception of the fingers. This means that no tooltips can be displayed, a status line cannot provide any additional information, and access to functions via the “right mouse button” (often on the left for left-handers) such as a context menu is not possible. Touching a link immediately leads to it being called up and then to a new page.

Link between web accessibility for humans and accessibility for robots

Increasingly, information is not only requested from the user , but also from software itself, generally via relatively simple scripts that transmit the data to more complex programs or a person in a suitable form. Because these run automatically or semi-automatically, they are commonly called robots or bot .

Internet search engines index the WWW with the help of automated programs ( web crawlers ) or robots. These programs perceive a side similar to that of visually impaired users. You can usually only evaluate text. Images, animations and the like remain hidden from them in most cases. The rule of thumb is: "Everything that causes problems for the visually impaired is also an obstacle for robots ."

However, it is not possible to generalize the rule of thumb. A blind person may still receive an output via an optional voice output. However, a robot that cannot analyze sounds will not be able to index any information. On the other hand, there are examples where blind humans can no longer get any information, but robots can still analyze something (such as structures or watermarks within images).

As a real problem prove the Captcha systems that have been designed to distinguish robots and humans ( C ompletely A utomated P ublic T uring test to tell C omputers and H Umans A part , "Fully automated Turing test to man and machine to distinguish "). The usually used images of distorted lettering must be recognized visually, so the test fails and blind and visually impaired people are treated like a "machine" by the system. There are extended Captcha methods with voice output, or systems that presumably ask “simple questions”, but these can be a problem for non-native speakers. In fact, the accessibility test proves to be a test of the Turing tests, and there is still no reliable method that can really tell man and machine apart.

Basic techniques for an accessible internet

The basic requirement for barrier-free websites is the correct use of web standards (valid HTML / XHTML ). The required strict separation of the structure of a document ( Document Object Model ) and its presentation ( layout ) can be achieved through the correct use of Cascading Style Sheets (CSS). There is no need to compromise on design. Some basic options:


Fixed font sizes are a barrier in some browsers because they are difficult to change by the user. The unit of measurement should be relative, especially for fonts, but also for areas, distances, etc. (information in em or%).

Meaningful structure

The most important rule for barrier-free websites is to use the HTML elements according to their meaning ( semantics ). This should be illustrated using the example of headings in the document. The HTML elements h1to are h6intended for headings and should also be used for marking:

<h1>Überschrift 1</h1>

An emphasis only by an enlarged font like with

<span style="font-size: 1.2em;">Überschrift 1</span>

works like a heading in a CSS-enabled browser for normal-sighted users, but is semantically incorrect and does not depict a structure. The fact that a text highlighted in this way is a heading is conveyed solely through the presentation and recognized by the (sighted) reader “at a glance” based on reading habits and typographical conventions. The screen reader of a blind Internet user, on the other hand, interprets the spanelement as normal text. This makes it more difficult for the user to orientate himself in the HTML document.

This example clearly shows that accessibility has less to do with "design" and more to do with the correct structure of (X) HTML source code. Positive side effect: Search engines evaluate semantically correct and valid websites, which has an impact on a better search result. This approach is comparable to the principle of the format template of a Word document. Anyone who does not work in a structured way here will constantly run into problems.

Positioning of elements

To place elements on a page, on the one hand table constructions can be used, on the other hand elements can be positioned with cascading style sheets using precise coordinates. The use of tables inflates the source text unnecessarily, since areas have to be defined that are not used at all. Above all, tables should only be used if the aim is to display tabular content, not to create a design grid. With Cascading Style Sheets, only elements that are required need to be defined. Overlapping of individual elements (foreground and background elements in different levels) is also possible. The use of DIV elements has proven itself here.

However, the independence of the displayed position from that in the source text is particularly advantageous. In the HTML document, the header area of ​​the visible content can only be defined at the end. If this is provided with banners, which are usually rather annoying for users with handicaps, these are defined at the end of the source text. This means that screen reader users do not have to “read” uninteresting things first, but can use the relevant content directly. Internal jump labels (anchors) such as jump to content (skip navigation) are useful.

Navigation elements such as menus should be defined as a list (UL, LI) and then optically designed as horizontal or vertical menus using a stylesheet. For a blind person, a list is better interpreted as a content index.

Acronyms and Abbreviations

Also Acronyms and abbreviations should with the appropriate HTML element abbr(for abbreviation to German: Abbreviation) will be awarded:

<abbr title="Barrierefreie Informationstechnik-Verordnung">BITV</abbr>

For reasons of simpler operation, it may be advisable to resolve an abbreviation in the following brackets: "BITV (Barrier-Free Information Technology Regulation)"

In modern browsers, this can be done using CSS (generated content, attribute selector, content property) without having to change the HTML code:

abbr[title]::after {
  content: ' ('attr(title)')';

Meaningful link texts

Screen readers allow visually impaired users to quickly comb through a text by jumping from link to link. The link texts read out by the software should be formulated in a useful way, i.e. describe the respective link specifically (do not use uniform, recurring terms for different link targets) and be self-explanatory, without context.

<!-- Falsch: -->
<a href="Linkziel-1">hier klicken</a>
<a href="Linkziel-2">online</a>
<!-- Richtig: -->
<a href="Linkziel-1">aussagekräftige Beschreibung</a>
<a href="Linkziel-2">verschiedene Texte für verschiedene Ziele</a>

Text alternative to graphic information

Information must not be available in the form of graphics alone, but must alternatively be accompanied by a descriptive text.

<!-- Falsch: -->
<img src="img/grauerloewe.png">
<!-- Richtig: -->
<img src="img/grauerloewe.png" alt="Zeichnung eines grauen Loewen, der auf einem Stein liegt.">

Images for layout purposes

Often images are only used for layout purposes, but not for conveying information. In order to comply with the required standards, i.e. to create valid HTML, images must be provided with an alternative text (ALT attribute). If the images are graphic elements for the page layout, alt text would be annoying for the blind, which is why the ALT attribute should be left empty; the picture is then ignored by screen readers. The method of using 1 × 1 pixel large transparent graphics to align elements, which are then placed in large numbers one behind the other, should be avoided entirely and CSS should be used instead for positioning. If an image is only used for the layout / design and does not convey any relevant information, it can also be defined as a background image in the stylesheet (background image).

Interactive buttons via CSS

Navigation menus are often implemented using JavaScript or plug-ins . This can make the source code unnecessarily large and locks users out if, for example:

  • JavaScript support is deactivated in the browser (e.g. for security reasons),
  • the required plug-ins are not installed
  • or the user is not able to perceive or operate the navigation due to a disability.

Most buttons on the Internet simply swap the background color or image, and text color and decoration. This is much easier with CSS and the source text is shrinking (bundling of format specifications in classes). This reduces the document size, which means that the transfer volume is smaller and the page is loaded faster. By outsourcing the CSS information to an external file, further improvements in terms of transfer volume and loading time can be achieved, as the formatting only has to be transferred to the user once - and not with each new call.

Unobtrusive JavaScript

Unobtrusive JavaScript (literally unobtrusive JavaScript , also: barrier-free JavaScript ) is a concept for the contemporary use of JavaScript in websites . JavaScript should therefore offer an expansion of the range of functions instead of being a prerequisite for functioning. The concept is becoming increasingly important , especially in connection with the barrier-free and mobile Internet .

Basic principles

  • Distribution of content, behavior and presentation of websites ( Model View Controller ).
  • Use of best practices to avoid problems with traditional JavaScript programming (different display in different web browsers , lack of scalability).
  • JavaScript as an extension of the functionality, not as a requirement.


Historically, JavaScript had the reputation of being a clumsy, unpolished programming language that was useless for "serious" software development. This is mainly due to inconsistent implementations of the scripting environment and the DOM in different browsers, as well as the extensive use of copy-paste source text. Runtime errors were so common and difficult to fix that many programmers foregone improvements as long as the script behaved more or less as desired. It was tolerated that such scripts did not work in some browsers.

The advent of standards-compatible browsers, JavaScript libraries, and better debugging tools made organized and scalable JavaScript code possible, and Ajax- based user interfaces even made it necessary.

Where JavaScript was previously only used for small, uncritical tasks, it is now the practice to also implement large, complicated projects that are often part of the core functionality of a website. Runtime errors are therefore not flaws, but fatal failures.

The concept of accessibility in the sense of JavaScript programming is shaped by the article Unobtrusive DHTML, and the power of unordered lists by Stuart Langridge. In this article, Langridge discusses the concept of strictly separating JavaScript from HTML . Since then he has presented this concept in detail in various articles and a book.

Practical use

The concept is supported in ASP.NET with MVC plug-in 3 using Ajax .

Online Content Accessibility Guidelines

To make the web more accessible, the W3C founded the Web Accessibility Initiative (WAI) . In 1999 this initiative published the first internationally recognized standard "Web Content Accessibility Guidelines 1.0" ( WCAG ). The current version WCAG 2.0 was published on December 11, 2008 after more than nine years of consultation.

European Union

There are 38 million people in the EU with a variety of disabilities, from mild disabilities (poor eyesight) to severe disabilities (such as blindness or severe multiple disabilities). The proportion of older people in the total population is steadily increasing. Currently about 20 percent of the population is over 60 years old.

The eEurope initiative (December 1999) on the information society names the participation of all, regardless of age and disability, as one of ten goals. The e-Europe action plan specifies the following projects: Introduction of the guidelines of the WAI by 2002 in public administration and design-for-all standards by 2003. On April 10, 2002, the European Council adopted a resolution in which the Member States were asked to do more to implement the guidelines of the WAI and to lay them down in national law .

With this supposedly already achieved, barrier-free access (eAccessibility) was no longer a priority topic in the 2005 action plan of the eEurope initiative. It was only taken up as a focus again in the i2010 initiative: in addition to the goals of creating a European information space and creating global top performance through innovations and investments in ICT research, an information society is required that includes all people, offers high-quality public services and contributes to increasing the quality of life.

The 2006 EU ministerial meeting in Riga, organized at the invitation of the Latvian government, focused on this third focus of the i2010 initiative . The Riga Ministerial Declaration was unanimously signed by 34 European countries - EU member states , candidate countries and the EFTA / EEA countries.


In Germany , four out of five people with disabilities use the World Wide Web . On May 1, 2002, the Act on Equal Opportunities for People with Disabilities and Amending Other Acts (Disability Equality Act - BGG) of April 27, 2002 came into force. In this law, the federal government has set rules for the creation of accessibility in information technology for its administration. The federal administration is thus obliged to make its publicly accessible internet and intranet offers accessible.

A corresponding ordinance ( barrier-free information technology ordinance - BITV ) by the Federal Ministry of the Interior and the Federal Ministry of Labor and Social Affairs regulates the requirements for this. Appendix 1 of the ordinance does not contain any requirements for basic technology ( server , router , protocols ), but rather lists requirements that are based on the guidelines of the WAI. The federal government lists a total of 14 requirements and more than 60 conditions to be fulfilled, classified in two priority levels. A transition period up to December 31, 2005 was planned for adapting existing offers at that time; since then, all offers have to take the regulations into account immediately.

The new version of the now outdated BITV is currently in the EU notification process. The deadline for comments from EU Member States was May 16, 2011.

In principle, the BITV is only aimed at institutions under public law that are subordinate to the federal government. Institutions and corporations in the federal states are covered by their own state equality laws. As a rule, the state laws are based on the BITV. It is controversial whether the equality laws require that pages are translated and offered in German sign language .

In the action alliance for barrier-free information technology , disability associations, research institutions and others have come together to promote the implementation of barrier-free accessibility on the Internet. AbI offers information on the subject of barrier-free internet on the information portal WOB11. The Aktion Mensch and the Digital Opportunities Foundation recorded between 2003 and 2010, the best German-language barrier-free websites with the BEE Award from. An official "barrier-free TÜV" test has not yet existed, however, as a standardized test procedure is difficult to define in terms of depth of detail and scope and comparability must be guaranteed. In addition, web offers - in contrast to, for example, barrier-free buildings  - can be changed easily and frequently, so a certificate would have to be checked regularly.

The BITV test is a test procedure for checking the accessibility of web offers. It was developed as part of the BIK - barrier-free information and communication project series and makes the requirements of the regulation on barrier-free information technology (BITV) manageable. BIK is funded by the Federal Ministry of Labor and Social Affairs. The test is offered by the BITV-Test Prüfverbund and carried out by self-help accessibility experts and various other test centers. The list 90plus presents exemplary barrier-free web offers, competent agencies and recommended content management systems. In addition to the BITV test, there is also a BITV self-assessment.

Digital barriers that impair the use of the Internet can be reported to the reporting office for digital barriers of the Federal Working Group on Self-Help .


Legal framework

The accessibility of the internet is based on the federal constitution . The Art. 7  para. 1 of the Federal formulated the principle of equality , also contains an explicit ban on discrimination for disabled people, and a national policy objective that the legislature for active realization of de facto equality obliged. The federal government, states and municipalities are committed to "guaranteeing equal treatment of disabled and non-disabled people in all areas of daily life." This has been implemented with the Federal Disability Equality Act and the Disability Employment Act since January 1, 2006.

In Section 6  (5) of the Federal Equal Opportunities for People with Disabilities Act, it is stated that a facility is barrier-free "if it is accessible and usable for people with disabilities in the generally customary manner, without any particular difficulty and generally without outside help." Basic accessibility requirements formulated in the guidelines for barrier-free web content WCAG 2.0 of the Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C).

With the E-Government Act of 2004 (implementation deadline January 2008), official websites that offer information or electronically support procedures were obliged to design them in such a way "that international standards on web accessibility also with regard to barrier-free access for disabled people be respected." (Section 1, Paragraph 3). WCAG 2.0 was also the international standard for this . The web presence of the administration and its electronic implementation ( e-government ) should also be mentioned: the General Administrative Procedure Act, the Delivery Act and the Signature and Trust Services Act.

In 2019 the Web Accessibility Act was published as a national law to implement Directive (EU) 2016/2012 on barrier-free access to the websites and mobile applications of public bodies . The requirements for accessibility for ICT products and services are specified together with a description of the test procedures and assessment methods for each accessibility requirement in the European standard EN 301 549 V2.1.2 (2018-08) , which means that all success criteria of conformity levels A and AA of the guidelines for accessible web content - WCAG 2.1 - must be observed. The exceptions formulated in national law or the EU directive are temporarily excluded.


Legal framework

In Switzerland, the accessibility of the state's internet offerings for people with disabilities is regulated in the federal constitution and the regulation of the accessibility of websites is specified in law and regulation.

  • The Disability Equality Act (BehiG) came into force on January 1, 2004. It aims to help people with disabilities as far as possible to a life that is comparable to that of non-disabled people.
  • In Article 10 of the Disability Equal Opportunities Ordinance (BehiV) , which came into force at the same time, it is described in detail that the information as well as the communication and transaction services must be accessible via the Internet for people with speech, hearing, visual and motor disabilities.

Specifically, the law means: Internet offers of the state ( federal government , cantons , municipalities , federal-related companies) must be accessible to disabled people without any aggravating conditions. Internet offers from private individuals are not obliged to make them suitable for the disabled, but they must not discriminate against any population group.

When the law and the ordinance came into force in 2004, the Federal Bureau for Equal Opportunities for People with Disabilities (EBGB) was created. Its task is to promote the equality of disabled and non-disabled people, as well as to work for the elimination of legal or actual disadvantages.

Guidelines and implementation

The federal guidelines for the design of barrier-free internet offers (P028) are based on the W3C standard WCAG 2.0, these internationally applicable guidelines were adopted unchanged. Compliance with all checkpoints of conformity level AA must be guaranteed. P028 also explicitly requires the accessibility of all presented PDF documents. PDF documents must be readable for people with disabilities or their content must be available in another, equivalent form, for example as a text document. As soon as the WAI puts a newer form of the WCAG into effect, the interdisciplinary committee must meet within three months and decide whether and how the standard P028 should be updated.

The Accessibility specialist group was formed within the Association for eGovernment Standards (eCH) for implementation at cantonal and communal level . It consists of federal representatives who contribute their experience, representatives from cantons and larger municipalities, as well as voluntary experts from the private sector and experts from the Access for All Foundation. The specialist group developed the open standard eCH-0059, consisting of guidelines and aids. Its purpose is to give those responsible and project staff guidelines on how an internet project can be handled without barriers. The guidelines list the necessary measures for each project phase.

In 2016, the Access for All Foundation published the second study on the accessibility of Swiss community websites for people with disabilities . On the one hand, it showed great progress in the accessibility of the websites of the federal authorities, and on the other hand, large and sometimes striking deficits in the websites of the cantons and federal-affiliated companies.

United States

It is estimated that 39.1 million Americans (15 percent of the population) are considered disabled. The USA is pioneering the introduction of accessibility in public administration at the federal and state level: As early as 1990, the Americans with Disabilities Act (ADA) was passed, the implementation of which is monitored by the Federal Ministry of Justice. Section 508 of the Rehabilitation Act , expanded in 1998, binds all federal agencies with regard to the information they provide. The regulations developed here by an independent federal institution have even been included in the procurement specifications and must be met by all companies that sell goods or services to the government.

Most individual states alternatively offer their Internet services in a "plain text" version or, such as Delaware , already completely meet all priority 1 requirements of the WAI. The e-government control center of Delaware is involved in promoting the implementation of the WAI guidelines for all administration offers of the state. There are examples in the municipal sector: the Internet presence of the city of Orlando (Florida) also meets the WAI requirements of priority 1.

Norms and standards

See also


  • Ansgar Hein, Jörg Morsbach: Buying Guide for Barrier-Free Internet 2007 . Barrier Compass 2007.
  • Jan Eric Hellbusch et al .: Barrier-free web design - practical handbook for web design and graphic program interfaces . dpunkt.verlag, Heidelberg 2005, ISBN 3-89864-260-7 .
  • Jan Eric Hellbusch, Thomas Mayer: Barrier-free web design - web design for people with physical limitations . KnowWare Verlag, Osnabrück 2005, ISBN 87-90785-75-4 .
  • Jan Eric Hellbusch, Kerstin Probiesch: Understanding and implementing accessibility. Web standards for an accessible and usable Internet . Heidelberg 2011, ISBN 978-3-89864-520-1 .
  • Angie Radtke, Michael Charlier: Barrier-free web design. Make attractive websites accessible . Addison-Wesley, Munich 2006, ISBN 3-8273-2379-7 .
  • Jan Dirk Roggenkamp: Barrier-free e-government . In: Neue Zeitschrift für Verwaltungsrecht ( NVwZ ), issue 11/2006, p. 1239
  • Werner Schweibenz, Brigitte Bornemann-Jeske: Accessibility on the Internet . In: IWP 56, special issue 8/2005, Dinges & Frick, Wiesbaden 2005, ISSN  1434-4653 .
  • Fabian Uehlin: Accessible websites . Redline Verlag, 2007, ISBN 978-3-8266-1674-7 .
  • Markus Riesch et al .: Swiss Accessibility Study 2007 . Zurich 2007

Web links

Individual evidence

  1. What are the barriers? , in: Barrier-free e-learning: Overcoming digital hurdles , , May 6, 2014, accessed on June 22, 2016
  2. Ralph Klein: Barrier-free design of user interfaces . In: display . tape 9 , 1994, pp. 93-110 .
  3. ^ Franz-Josef Hanke: 10 years AKBI. Barrier-free Internet working group celebrates its birthday. (No longer available online.) AKBI, October 14, 2008, archived from the original on February 15, 2009 ; Retrieved February 18, 2009 .
  4. Martin Stehle: Re: Barrier-ARM. (No longer available online.) Fraunhofer Institute for Applied Information Technology, October 4, 2004, archived from the original on November 3, 2012 ; Retrieved February 18, 2009 .
  5. Peter Purgathofer: CAPTCHAs in the field of tension between accessibility and security. (MP3) Lecture on the subject of "Barrier-free User Interface Design". Martin Ladstätter, October 19, 2007, accessed June 19, 2013 .
  6. BITV requirement 1 (text equivalents and alternatives)
  7. Jeremy Keith: Behavioral Separation . June 20, 2006. Retrieved March 6, 2011.
  8. ^ Tommy Olsson: Graceful Degradation & Progressive Enhancement . February 6, 2007. Retrieved March 6, 2011.
  9. ^ Stuart Langridge: Unobtrusive DHTML, and the power of unordered lists . November 2002. Retrieved August 7, 2008.
  10. ^ Building dynamic websites . August 9, 2006. Retrieved May 18, 2010.
  11. The sensible use of JavaScript . ( Memento from September 2, 2011 in the Internet Archive ) Selfhtml
  12. ^ Jon Galloway, Phil Haack, Brad Wilson, K. Scott Allen: Professional ASP.NET MVC 3 , p. 9
  13. Ben Caldwell, Michael Cooper, Loretta Guarino Reid, Gregg Vanderheiden: Web Content Accessibility Guidelines (WCAG) 2.0. W3C, December 11, 2008, accessed December 13, 2008 .
  14. a b c d e f g h See norms and standards
  15. heb: New web standard for accessibility WCAG 2.0 adopted. heise online, December 12, 2008, accessed on December 13, 2008 .
  16. ^ EEurope - An Information Society for All ( Memento of February 11, 2007 in the Internet Archive ), EU activity reports
  17. Action Plan 2005 (PDF; 87 kB)
  18. ^ I2010 initiative ( Memento from February 16, 2007 in the Internet Archive )
  19. Riga Ministerial Declaration ,, German version in HTML
  20. Article on the overview of the equality laws ,
  21. ^ Status of implementation of the BITV in German state law. Action alliance for barrier-free information technology (AbI)
  22. AbI
  23. WOB11
  24. Simply for everyone - an initiative of the German Disability Aid - Aktion Mensch e. V.
  25. Digital Opportunities Foundation
  26. Certification ( Memento from November 20, 2012 in the Internet Archive ) - barrier-free communication!
  27. BIK project series - barrier-free information and communication
  28. BITV test - The BITV test
  29. Christian Radek: Barrier-free e-learning: Overcoming digital hurdles , , May 6, 2014, accessed on June 22, 2016
  30. a b Web Accessibility - Internet access for everyone , Platform Digital Austria, - Information from the federal government on the state of e-government
  31. Federal Disability Equality Act in the current version in the RIS
  32. Disability Employment Act in the current version in the RIS
  33. E-Government Act in the current version in the RIS
  34. General Administrative Procedure Act in the current version in the RIS
  35. ^ Service Act in the current version in the RIS
  36. Signature and Trust Services Act in the current version in the RIS
  37. Web Accessibility Act as amended in the RIS
  38. On the implementation of Directive (EU) 2016/2102 and the Web Accessibility Act , Administrative Wiki of the Republic of Austria
  39. EBGB website
  42. Guide eCH-0059 ( Memento from April 19, 2014 in the Internet Archive ) (PDF; 98 kB)
  43. Aid eCH-0059 ( Memento from January 31, 2012 in the Internet Archive ) (PDF; 162 kB)
  44. Inventory of the accessibility of Swiss community websites (PDF)