Accessibility features

This page lists the features used to facilitate the accessibility, compatibility and interoperability of the content of the LONDON O3 Web site. We are committed to making the content of the site as accessible as possible and welcome your feedback.

Standards compliance

All areas of the site comply with Level AA (the intermediate level) of the World Wide Web Consortium Web Accessibilty Initiative Web Content Accessibility Guidelines 1.0 to promote accessibility, compatibility and interoperability.

The LONDON O3 Web site follows the W3C recommendations for Extensible HyperText Markup Language 1.0 and Cascading Style Sheets 2. In both cases (XHTML and CSS), the markup of all pages is valid.

Access keys

Most Web browsers support jumping to specific links by typing keys defined on the Web site. In Windows, you can press Alt + an access key (if you are using Internet Explorer, press Return to follow the link); on Macintosh, you can press Control + an access key.

Access keys are defined because not all users are able to use a mouse, and several alternative browsing devices do not employ a ‘point and click’ interface.

In line with the Guidelines for UK government websites produced by the Office of the e-Envoy, the LONDON O3 site defines the following access keys:

• access key 1 (Alt+1) - home page
• access key s (Alt+S) - skip main navigation links (in certain browsers)
• access key 3 (Alt+3) - site map
• access key 4 (Alt+4) - search facility
• access key 8 (Alt+8) - terms of use
• access key 9 (Alt+9) - feedback
• access key 0 [zero] (Alt+0) - accessibility statement

Visual design

The LONDON O3 Web site uses Cascading Style Sheets for visual layout and design, avoiding the use of HTML tables and frames which can impede accessibility. A dedicated print style sheet is used to optimise each page for printing.

Font sizes are defined relatively, which means that they are determined by the user’s preferences. Text can be resized using the browser’s mechanism (View→Text Size | View→Text Zoom | View→Zoom | Ctrl++/Ctrl+-). If you have a mouse wheel, you can also hold down the Ctrl key and rotate the mouse wheel to make the text larger and smaller as required.

A Web standards compliant visual browser will display the pages as they were intended. However, all the content of the site is accessible using any browser or Internet device.

Document structure and markup

The content of each page is contained in structural XHTML. For example, <h1> tags are used for page titles and <h2> tags are used for main page headings. Similarly, abbrevations and acronyms are marked up with <abbr> and <acronym> tags. Emphasis is added using the meaningful <em> and <strong> tags, rather than <i> (italics) and <b> (bold) tags, which are merely visual.

Logically ordered documents make sense when read (by text-only browsers, for instance) in a linear fashion. Markup structured in this way has the advantage of providing some Web devices with a quick summary of the content of a page, by listing titles, headings and links, for example. Structural tags provide alternative browsers (especially screen readers) with the opportunity to add meaning to the content of a page. Using structural markup also improves automated searching, both within the site and by search engines.

Navigation aids

For users of screen readers and other serial browsers, ‘skip navigation’ links (access key S) are provided to allow visitors to bypass the navigation and go directly to the main content of each page.

Links to the site map (access key 3) and search facility (access key 4) are provided on all pages of the Web site. Each page contains several <link> elements to provide details of the relationships between different sections and pages of the site to those browsers that support its use.

Links

Where appropriate, links are provided with extra information in the title attribute of the <a> tag. In conventional browsers, this detail usually appears as a tooltip when the mouse hovers over a link. Screen readers and other devices also have methods of reading or displaying this information.

Wherever possible, link text is written to make sense when taken out of context. Browsing devices that can extract a list of links from a page will therefore render meaningful content.

No links use the javascript: pseudo-protocol. This means that browsers that do not support JavaScript and users who have disabled JavaScript are not excluded from any content. It also allows search engines, which do not execute JavaScript code when indexing the Web, to access all the content of the site.

Links will not open new windows.

Images

All non-background images used on the site have alt attributes to provide alternative text that will appear in browsers that do not support images.

Forms

Interactive forms on the site make use of several features to improve accessibility. These include:

labelling of form elements

The <label> tag allows text to be associated with a particular form field, assisting screen readers to intelligently announce what a particular input element is by reading the label;

grouping of related form elements

Elements forming convenient groups of fields within forms are explicitly related using the <fieldset> tag. This means that forms can be split into discrete sections, aiding their completion by users with assistive technologies.