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is accepted as valid for the "body" element even though the value "fffff" is missing a preceding '#' character and contains only five (instead of six) hexadecimal digits. Also, for the "img" element, width="really wide" is also accepted as valid. DTD-based validators are technically not able to test
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Pages may not display as intended in all browsers, even in the absence of validation errors and successful display in other browsers. The only way to ensure that pages always display as intended is to test them in all browsers expected to render them correctly.
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has removed the use of DTD in favor of a "Living
Standard", the traditional Markup Validation Service is not applicable to these formats. Validation is instead performed using an open-source "Nu Validator", an instance of which is provided by W3C.
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While the W3C and other HTML and XHTML validators will assess pages coded in those formats, a separate validator like the W3C CSS validator can check that there are no errors in the associated
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based upon his works. In
November 2008, the W3C released the validator.nu HTML5 engine and the ability to check documents for conformance to HTML5.
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conformance. Though W3C validation is important for browser compatibility and site usability, it has not been confirmed what effect it has on
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are often tolerant of certain types of error, and may display a document successfully even if it is not syntactically correct. Certain other
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287:"ANNOUNCE: HaL Interactive HTML Validation Service"
16:Validator service by the World Wide Web Consortium
333:"What's New at The W3C Markup Validation Service"
313:"History of the Kinder, Gentler HTML Validator"
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86:search engine optimization
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360:"About the CSS Validator"
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50:Markup Validation Service
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154:Limitations
138:Many major
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1009:Deprecated
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967:Guidelines
875:XHTML+SMIL
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669:Timed text
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366:2012-06-24
342:2016-05-31
318:2008-06-28
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226:References
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192:HTML Tidy
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