Note: Below is the original page from the Bootlint documentation, some of the info here might not apply to Bootlint-NG!

The contained elements do not need to be in a row/column at all since it will render the same way without using the grid in the first place. Using a combination of grid classes that includes a .col-*-12 is ok.

Wrong:

<div class="row">
    <div class="col-md-12">
        <p>Content here</p>
    </div>
</div>

Right:

<p>Content here</p>

Another example:

<div class="row">
    <div class="col-sm-6 col-md-12">
        <p>This is fine since it also uses other grid sizes</p>
    </div>
</div>