Code Guide
Standards for developing consisten and sustainable HTML and CSS
...Use soft tabs with two spaces, they're the only way to guarantee code renders the same in any environment. Nested elements should be indented once (two spaces). Always use double quotes, never single quotes, on attributes. Don't include a trailing slash in self-closing elements, the HTML5 spec says they're optional. Don’t omit optional closing tags (e.g. </li> or </body>). Enforce standards mode and more consistent rendering in every browser possible with this simple doctype at the beginning of every HTML page. ...