<span class="align-baseline">baseline</span> <span class="align-top">top</span> <span class="align-middle">middle</span> <span class="align-bottom">bottom</span> <span class="align-text-top">text-top</span> <span class="align-text-bottom">text-bottom</span>
<div class=”row”> <div class=”col-6 align-self-center”> <div class=”card card-block”> Center </div> </div> </div>
<div class="my-auto"> ...inner divs and content... </div>