Why YUI Reset CSS doesn't pass Validation?...

Is it valid to put h3 (or any heading) inside td tags?...

Getting rid of <center> tag...

What is the correct way to mark up the author of a (block)quote?...

w3c compliance - html 5 - "Error: The document content type is not HTML : undefined"...

Error: Stray end tag head...

htmlspecialchars "Forbidden code point" validation error...

nu validator is ok with unclosed tags...

Correct way to insert favicon link tag in SVG...

Microdata itemprop causes W3C validator error...

DOMDocument saveHTML is not returning correct HTML Standards for "IMG", "INPUT"...

Validation errors (like "Stray start tag html") that I can't seem to shake on header.p...

Dublin Core and Metaname cause W3C Validation Issues in HTML5 page...

Unable to validate html due to missing quotation for = string...

Errors "Stray end tag head" and "An body start tag seen but an element of the same ty...

Are unquoted data URIs valid in CSS?...

"Attribute itemprop not allowed on element meta at this point"...

Can the aside tag be first in an article?...

W3C CSS validator error: 'Property text-rendering doesn't exist : geometricPrecision'...

Invalid quotes in URL...

Is it semantic for <li> to have block elements like figure, audio, video?...

W3C validation for <ui-select>...

W3C HTML validator no longer accepts scoped styles...

W3C validation generating error...

Node.js equivalent of this curl request...

Safari and Firefox not displaying site correctly, but Chrome is working well...

Hosting W3 XML Schema files locally...

W3C Validation results don't match source code in console?...

Markup Validation, Errors found...

Minimum requirements for script tag & page validity...