From W3C Wiki
The <i> element represents an span oftext that offset from the normal prose.
- Some examples of cases:
- taxonomic designation
- technical term
- idiomatic phrase from another language
- ... Some other prose whose typical typographic presentation is italicized.
- Authors are encouraged to consider whether other elements might be more applicable than the i element, for instance the em element for marking up stress emphasis, or the dfn element to mark up the defining instance of a term.
- Authors can use the class attribute on the i element to identify why the element is being used, so that if the style of a particular use is to be changed at a later date, the author doesn't have to go through the entire document (or series of related documents) annotating each use. [Example A] For more information see W3C Internationalization articles [Using <b> and <i> elements]
See global attributes.
<p>The <i class="taxonomy">Felis silvestris catus</i> is cute.</p>
Terms in languages different from the main text should be annotated with lang attributes [try it]:
<p>There is a certain <i lang="fr" class="idiomatic">je ne sais quoi</i> in the air.</p>
The HTML5 specification defines the <i> element in 4.6.16 The i element.