9. Style Sheets

9.1 Organise documents so they may be read without style sheets

Guide to this standard

Web sites that use style sheet techniques ‘degrade gracefully’ (as defined in the Glossary of Key Concepts), so that the site remains fully functional if style sheet techniques are ignored. Test for graceful degradation by viewing the site with a text browser, such as Lynx, or use Firefox Web Developer toolbar to disable CSS.

For example, when an HTML document is rendered without associated style sheets, it must still be possible to read the document in the logical order it was intended with style sheets.

This standard covers the W3C WAI checkpoint 6.1 (http://www.w3.org/TR/WCAG10-TECHS/#tech-order-style-sheets) for NZ government agencies.

Rationale for this standard

Style sheets are not consistently supported by different browsers, and some browsers (generally older browsers) do not support them at all.

For further detail, see

Irish National Disability Authority http://accessit.nda.ie/it-accessibility-guidelines/web/guidelines/priority-1/1-12

9.2 Use style sheets to control layout and presentation of page and elements

Guide to this standard

Use HTML structural elements, such as H1 to H6, OL, and UL, to denote document structure rather than custom styles. People who using non-visual browsers or browsers that ignore style sheets are therefore not disadvantaged.

You may use selectors, properties and values that are defined in CSS2, but only where you are sure they will ‘degrade gracefully’ (as defined in the Glossary of Key Concepts) in browsers that do not correctly interpret CSS2, or do so poorly.

This standard covers the W3C WAI checkpoint 3.3 (http://www.w3.org/TR/WCAG10-TECHS/#tech-style-sheets) for NZ government agencies.

Related Standards

9.1 - Organise documents so they may be read and still function without style sheets.

Rationale for this standard

As stated by the Irish National Disability Authority, “Using style sheets separates structure and presentation which brings several benefits, including improved accessibility, manageability, and portability”.

This complements the use of HTML 4.01, whereby the W3C reinstated HTML as primarily a structural document mark-up language and, alongside this, encourages the use of style sheets for presentation.