Phrases may be marked up according to idiomatic usage, typographic appearance, or for use as hyperlink anchors.
User agents must render highlighted phrases distinctly from plain text. Additionally, <EM> content must be rendered as distinct from <STRONG> content, and <B> content must rendered as distinct from <I> content.
Phrase elements may be nested within the content of other phrase elements; however, HTML user agents may render nested phrase elements indistinctly from non-nested elements:
plain <B>bold <I>italic</I></B> may be rendered the same as plain <B>bold </B><I>italic</I>