E039 - Herst/bootlint-ng GitHub Wiki
Note: Below is the original page from the Bootlint documentation, some of the info here might not apply to Bootlint-NG!
The .navbar-left and .navbar-right alignment classes should only be used within navbars (.navbar), since this is their express purpose. Using them outside of a navbar is nonsensical.
Wrong:
<body>
  <div class="navbar-left">
    ...
  </div>
</body>Right:
<nav class="navbar navbar-default">
  <div class="container-fluid">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-42">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="#">Brand</a>
    </div>
    <div class="collapse navbar-collapse" id="bs-example-navbar-42">
      <p class="navbar-text navbar-right">Signed in as Mark Otto</p>
    </div>
  </div>
</nav>