Rules
Rules are used to visually segment your user interface. There are three variations of rules.
<h1>Large Rule</h1>
<hr class="large" />
<h2>Normal Rule</h2>
<hr />
<h3>Small Rule</h3>
<hr class="small" />Usage
The standard sized rule is created whenever you use the <hr> tag:
<hr />
You can control the size of a rule by using the small and large classes.
Guidelines
Using Rules with Titles
Place rules below titles, not above them. A large rule should always be accompanied with text, although the other rule sizes can be on their own.
Don't Overuse Rules
Too many rules can be visually confusing. Keep it simple by restricting the number of rules you use.