How would you abbriviate XHTML to an arbitrary number of words?

<p>
    Proin tristique dapibus neque. Nam eget purus sit amet leo
    tincidunt accumsan.
</p>
<p>
    Proin semper, orci at mattis blandit, augue justo blandit nulla.
    <span>Quisque ante congue justo</span>, ultrices aliquet, mattis eget,
    hendrerit, <em>justo</em>.
</p>

<p>
    Proin tristique dapibus neque. Nam eget purus sit amet leo
    tincidunt accumsan.
</p>
<p>
    Proin semper, orci at mattis blandit, augue justo blandit nulla.
    <span>Quisque ante congue...</span>
</p>

- p
    - Proin tristique dapibus neque. Nam eget purus sit amet leo
      tincidunt accumsan.
- p
    - Proin semper, orci at mattis blandit, augue justo blandit nulla.
    - span
          - Quisque ante congue justo
    - , ultrices aliquet, mattis eget, hendrerit,
    - em
          - justo
    - .