<ul class="nav nav-tabs">
<li class="nav-item">
<a class="nav-link active" href="#">Active</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" data-toggle="dropdown"
href="#" role="button" aria-haspopup="true" aria-expanded="false">
Dropdown</a>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
</div>
</li>
</ul>
You don't need to remember all CSS classes. Just use the Bootstrap Editor instead.