These labels might come in handy for labeling things, such as POST, DELETE, UPDATE methods for endpoints. You can use any classes from Bootstrap in your content.
<span class="label label-default">Default</span>
<span class="label label-primary">Primary</span>
<span class="label label-success">Success</span>
<span class="label label-info">Info</span>
<span class="label label-warning">Warning</span>
<span class="label label-danger">Danger</span>
Default
Primary
Success
Info
Warning
Danger
You can have a label appear within a heading simply by including the span tag in the heading. However, you can't mix Markdown syntax with HTML, so you'd have to hard-code the heading ID for the auto-TOC to work.