<div class="mr-0 bg-primary d-inline-block">Spaced Div</div>
<div class="mr-1 bg-primary d-inline-block">Spaced Div</div>
<div class="mr-2 bg-primary d-inline-block">Spaced Div</div>
<div class="mr-3 bg-primary d-inline-block">Spaced Div</div>
<div class="mr-4 bg-primary d-inline-block">Spaced Div</div>
<div class="mr-5 bg-primary d-inline-block">Spaced Div</div>
<!-- respsonsive viariations -->
<div class="mr-sm-5 d-inline-block bg-primary">Spaced Div</div>
<div class="mr-md-5 d-inline-block bg-primary">Spaced Div</div>
<div class="mr-lg-5 d-inline-block bg-primary">Spaced Div</div>
<div class="mr-xl-5 d-inline-block bg-primary">Spaced Div</div>
You don't need to remember all CSS classes. Just use the Bootstrap Editor instead.