I have a small pet peeve that I’m going to share with you. On the nights when I finish up a new CSS3 tutorial for Nettuts+ — typically while listening to my favorite Biebster songs — I click publish, and then wait to see how long it’ll take before a reader leaves a comment containing the phrase, “But it doesn’t validate.”

— Jeffrey Way

Jeffrey Way’s article sums the subject of web validation  far more perspicuously then I ever could.

http://net.tutsplus.com/articles/general/but-it-doesnt-validate/