XHTML is aimed at marking up simple text documents containing:

• Headings: h1 h2 h3 h4 h5 h6
• Paragraphs with parts emphasised: p em strong
• Lists: ul ol li dl dt dd
• Images: img
• Tables
• Objects
• Forms
• Various other markup: address blockquote acronym ...

Each element has precise rules about where it can appear and what elements it can contain

Page author should use the most appropriate markup