You can add a one line description to the subhead with .Subhead-description.
<divclass="Subhead-heading">Subhead with description</div>
<divclass="Subhead-description">The subhead is a subdued header style with a light bottom border.</div>
For longer descriptions, it is recommended that you use a paragraph below the Subhead.
This is a longer description that is sitting below the Subheader. It's much longer than a description that could sit comfortably in the Subhead. It might even have <strong>bold</strong> text.<ahref="#">Click to learn more.</a>
You can add a button or something to the right of .Subhead-heading with the .Subhead-actions element.
<divclass="Subhead-heading">Subhead with button</div>