6.5 Use structural and semantic markup properly and validate code

Markup such as headings, paragraphs, lists, definitions, and quotes add useful semantic information. Markup used for presentation purposes doesn't.

Valid code ensures the widest possible acceptance by the multitude of devices, and a clearer upgrade path to new standards.

Use the structural markup wherever possible to add meaning to a page
Do not use semantic markup for presentation effects, e.g.
- <blockquote> for indents
- <th> for centre align in layout tables
- <address>, <em> for italics (default style for these elements)
- <strong> for bold (default style)
Do not use presentation elements to simulate structure, e.g.
- Bolding and increased font size to make a heading, use <h1>, etc.
Use CSS where possible, see ref
Do not use deprecated features of HTML (see examples list)
Write HTML and CSS according to the specified standards - validate against those standards

Tip: The quotation tag <q> isn't well supported by browsers at the moment - avoid using for now.

Tip: Many code validators will help weed out deprecated tags, syntax problems, and assist you to code to standards, e.g.

The W3C CSS Validation Service (jigsaw.w3c.org/css-validator)

Poor: B to mark an important word, blockquote to indent, em to make italic

Structural / semantic coding - use these:

Deprecated - Do not use these:

Recommendations