<P> In order for search - engine spiders to be able to rate the significance of pieces of text they find in HTML documents, and also for those creating mashups and other hybrids, as well as for more automated agents as they are developed, the semantic structures that exist in HTML need to be widely and uniformly applied to bring out the meaning of published information . </P> <P> While the true semantic web may depend on complex RDF ontologies and metadata, every HTML document makes its contribution to the meaningfulness of the Web by the correct use of headings, lists, titles and other semantic markup wherever possible . This "plain" use of HTML has been called "Plain Old Semantic HTML" or POSH . The correct use of Web 2.0' tagging' creates folksonomies that may be equally or even more meaningful to many . HTML 5 introduced new semantic elements such as section, article, footer, progress, nav, aside, mark, and time . Overall, the goal of the W3C is to slowly introduce more ways for browsers, developers, and crawlers to better distinguish between different types of data, allowing for benefits such as better display on browsers on different devices . </P> <P> Presentational elements are not deprecated in current HTML (4.01) and XHTML recommendations, but were recommended against . In HTML 5 some of those elements, such as i and b are still specified as their meaning has been clearly defined "as to be stylistically offset from the normal prose without conveying any extra importance". </P> <P> In cases where a document requires more precise semantics than those expressed in HTML alone, fragments of the document may be enclosed within span or div elements with meaningful class names such as <span class = "author"> and <div class = "invoice">. Where these class names are also a fragment identifier within a schema or ontology, they may link to a more defined meaning . Microformats formalise this approach to semantics in HTML . </P>

Recommended approach for providing semantic meaning to html elements