Any text that is directly contained inside a block container element (not inside an inline element) must be treated as an anonymous inline element.
Anonymous inline boxes do not have an associated inline-level element.
In a document with HTML markup like this:
<p>Some <em>emphasized</em> text</p>
- the p generates a block box
- The box for “emphasized” is an inline box generated by an inline element (<em>),
- The other boxes (“Some” and “text”) are inline boxes
Such anonymous inline boxes inherit inheritable properties from their block parent box. Non-inherited properties have their initial value.
White space content that would subsequently be collapsed away according to the white-space property does not generate any anonymous inline boxes.