A web page is authored in conformance with instructions, especially prohibitions, of the newer stable specification of the technology on which the page depends.
Suggestion for Priority Level (A/AA/AAA)
Level AA (or A)
Related Glossary additions or changes
newer stable specification: The latest specification document for a specific technology that is widely supported by user agents and accepted by many authors. The specification document could be a W3C Recommendation, an ISO standard or a vendor-specific technical document.
What Principle and Guideline the SC falls within.
Principle 4, Guideline 4.1
Description
Along with advances in technologies and accumulation of knowledges by the Web community, specifications for Web technologies are evolving day by day. Consequently, multiple stable specifications are introduced for a single Web technology. For example, HTML has several major stable specifications, including HTML 3.2, HTML 4 and HTML 5. Among them, HTML5 is considered as a newer and more stable specification. Generally, techniques defined in older specifications may be obsoleted in newer specifications for some rational reasons based on knowledges discovered after the publication of older specifications. For instance, HTML 5 obsoleted multiple elements defined in HTML 4 [1].
Newer specifications often strictly forbid use of obsoleted techniques. In HTML 5, for example, obsoleted elements are regarded as “non-conforming” and they “must not be used” by authors of HTML documents. Web content developers are required to follow those instructions in accordance with the meaning of requirement strength keywords (such as “should”, “must” and “must not”) defined separately, e.g. RFC 2119 [2] for W3C specifications [3] or ISO/IEC Directives Part 2 [4] for ISO standards [5]. Therefore, Web content developers need to strictly avoid use of obsoleted features in order to create contents with new technologies and with conformance to newer specifications defining those new technologies.
As stated above, early techniques are obsoleted for rational reasons, such as inefficiency or deterioration of usability. Thus, employing newer specifications and avoiding obsoleted features would improve robustness of Web contents. For this sense, conformance to instructions given by the latest stable specifications should be endorsed to Web content creators for good reasons. For the same purpose, Web content creators also should to keep their contents up to date with the latest specifications.
Note 1: Contents existing on non-rewritable media (e.g. CD-ROM) are hard to be updated. In such cases, this proposal is considered to be satisfied as long as they conform to the latest stable specifications available at the time the contents are recorded on such media.
Note 2: Some techniques in Techniques for WCAG 2.1 do and will do conflict with this proposal at present of in the future. These techniques are highly anticipated to be revised soon so that they do not conflict with prohibition by newer stable specifications.
Note 3: Each technique in Techniques for WCAG 2.1 may refer to the latest Web technical specifications in background for convenience.
By following prohibitions of newer stable specifications, it enables to avoid using obsoleted technologies (for instance, https://www.w3.org/TR/html/obsolete.html#obsolete). As a result, users can have robustness.
Testability
For HTML and ARIA, this SC can be tested by the Nu HTML checker.
In case of CSS, this SC can be tested by the CSS validator.
For other technologies, syntax checkers could be available for tests.
SC Shortname
Harmonization with other newer specifications
SC Text
A web page is authored in conformance with instructions, especially prohibitions, of the newer stable specification of the technology on which the page depends.
Suggestion for Priority Level (A/AA/AAA)
Level AA (or A)
Related Glossary additions or changes
newer stable specification: The latest specification document for a specific technology that is widely supported by user agents and accepted by many authors. The specification document could be a W3C Recommendation, an ISO standard or a vendor-specific technical document.
What Principle and Guideline the SC falls within.
Principle 4, Guideline 4.1
Description
Along with advances in technologies and accumulation of knowledges by the Web community, specifications for Web technologies are evolving day by day. Consequently, multiple stable specifications are introduced for a single Web technology. For example, HTML has several major stable specifications, including HTML 3.2, HTML 4 and HTML 5. Among them, HTML5 is considered as a newer and more stable specification. Generally, techniques defined in older specifications may be obsoleted in newer specifications for some rational reasons based on knowledges discovered after the publication of older specifications. For instance, HTML 5 obsoleted multiple elements defined in HTML 4 [1].
Newer specifications often strictly forbid use of obsoleted techniques. In HTML 5, for example, obsoleted elements are regarded as “non-conforming” and they “must not be used” by authors of HTML documents. Web content developers are required to follow those instructions in accordance with the meaning of requirement strength keywords (such as “should”, “must” and “must not”) defined separately, e.g. RFC 2119 [2] for W3C specifications [3] or ISO/IEC Directives Part 2 [4] for ISO standards [5]. Therefore, Web content developers need to strictly avoid use of obsoleted features in order to create contents with new technologies and with conformance to newer specifications defining those new technologies.
As stated above, early techniques are obsoleted for rational reasons, such as inefficiency or deterioration of usability. Thus, employing newer specifications and avoiding obsoleted features would improve robustness of Web contents. For this sense, conformance to instructions given by the latest stable specifications should be endorsed to Web content creators for good reasons. For the same purpose, Web content creators also should to keep their contents up to date with the latest specifications.
Note 1: Contents existing on non-rewritable media (e.g. CD-ROM) are hard to be updated. In such cases, this proposal is considered to be satisfied as long as they conform to the latest stable specifications available at the time the contents are recorded on such media.
Note 2: Some techniques in Techniques for WCAG 2.1 do and will do conflict with this proposal at present of in the future. These techniques are highly anticipated to be revised soon so that they do not conflict with prohibition by newer stable specifications.
Note 3: Each technique in Techniques for WCAG 2.1 may refer to the latest Web technical specifications in background for convenience.
Benefits
By following prohibitions of newer stable specifications, it enables to avoid using obsoleted technologies (for instance, https://www.w3.org/TR/html/obsolete.html#obsolete). As a result, users can have robustness.
Testability
For HTML and ARIA, this SC can be tested by the Nu HTML checker.
In case of CSS, this SC can be tested by the CSS validator.
For other technologies, syntax checkers could be available for tests.
Techniques
G134: Validating Web pages
https://www.w3.org/TR/WCAG20-TECHS/G134
H88: Using HTML according to spec
https://www.w3.org/TR/WCAG20-TECHS/H88
Acknowledgement
This proposal is submitted with a private support by @makotom .