A very well compiled thread at WebproWorld discusses what W3C is and why it is so important to conform to its standards.
W3C refers to the World Wide Web Consortium working to develop open standards for the World Wide Web (abbreviated WWW or W3) so that Web documents can be consistently displayed across all platforms.
Founded in 1994 the consortium is still the main web standard against which all websites are evaluated. The most well known W3C tool is Markup Validation Service that checks the markup validity of Web documents in HTML, XHTML, SMIL, MathML, etc. Other valuable tools include RSS/Atom feed validator or CSS validator, Mobile content checker, and broken link checker.
The benefits of conforming to W3C standards include:
- Search Engine Visibility (related discussions);
- Browser Compatibility (including voice browsers, Braille browsers or hand-held browsers, screen readers, etc).
- Convertibility (W3C compliant documents can be easily converted to other formats including database and word document.);
- Stability (W3C codes ensure both forward and backward compatibility which helps the data written in old standard to work in newer browsers.);
- Universality (W3C standards-compliant coding ensures that each developer easily understand the existing coding conventions and the new designers also pick up where their predecessors left off.)
Still, the criticism in webmaster and SEO communities does take place:
- many of the standards are too old and are based on the last century realia (e.g. according to W3C any page limit is twenty kilobytes which is not necessary to conform to with today’s high-speed Internet connections);
- the market is moving many times faster than the W3C committee (e.g. mobile Internet which evolves too fast for both W3C and Google to compile);
- some of W3C tools are often broken or too slow which is unacceptable when speaking about the committee aiming at standardized www;
- standards have a tendency to “stifle creativity“, never allowing web developers to push the boundaries of what is acceptable in order to see what might be accomplished outside the rules.
So my main question is: is checking a website against W3C validity part of your on-site diagnostics? Do you still care? Do you pay attention to all errors or only to to major ones (skipping what you deem unimportant)?