span in bootstrap 4 code example

Example 1: bootstrap Badges

Badges scale to match the size of the immediate parent element by 
using relative font sizing and em units.
<h1>Example heading <span class="badge badge-secondary">New</span></h1>
<h2>Example heading <span class="badge badge-secondary">New</span></h2>
<h3>Example heading <span class="badge badge-secondary">New</span></h3>
<h4>Example heading <span class="badge badge-secondary">New</span></h4>
<h5>Example heading <span class="badge badge-secondary">New</span></h5>
<h6>Example heading <span class="badge badge-secondary">New</span></h6>
<button type="button" class="btn btn-primary">
  Profile <span class="badge badge-light">9</span>
  <span class="sr-only">unread messages</span>
</button>

Example 2: bootstrap badges Links

Using the contextual .badge-* classes on an <a> element quickly provide 
actionable badges with hover and focus states.

<a href="#" class="badge badge-primary">Primary</a>
<a href="#" class="badge badge-secondary">Secondary</a>
<a href="#" class="badge badge-success">Success</a>
<a href="#" class="badge badge-danger">Danger</a>
<a href="#" class="badge badge-warning">Warning</a>
<a href="#" class="badge badge-info">Info</a>
<a href="#" class="badge badge-light">Light</a>
<a href="#" class="badge badge-dark">Dark</a>