What is the Bootstrap card-block class?

Question

I don't see the class card-block mentioned in the reference documentation, but I have seen this class used in a few examples. This is the officially reference:

https://getbootstrap.com/docs/4.0/components/card/

And this is an example where the class is used:

https://www.codeply.com/go/pVsGQZVVtG/bootstrap-4-no-gutters-(spacing)

I've seen cards used but what is this card-block class?

Example:

<div class="row">
  <div class="col-3">
    <div class="card">
      <div class="card-block">
        normal
      </div>
    </div>
  </div>
  <div class="col-4">
    <div class="card">
      <div class="card-block">
        normal
      </div>
    </div>
  </div>
  <div class="col">
    <div class="card">
      <div class="card-block">
        normal
      </div>
    </div>
  </div>
</div>

Answer 1

The card-block class was used on an Alpha Release version of Bootstrap 4 and doesn't exists on the current release. You can read the documentation of that class on the link: card-block on v4-Alpha. There says that:

The building block of a card is the .card-block. Use it whenever you need a padded section within a card.

Like I already mention, this class do not exist on the currently v4.1.3 release or another superior version. You can check with the browser inspector tool on the next example and see that there is no CSS style related to the card-block class but there exists CSS style related to, like an example, the officially documented card-header or card-body classes.

Link to official documentation about cards: Bootstrap Cards

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<div class="container-fluid">

  <div class="card">
    <div class="card-block">
    card-block
    </div>
  </div>
  <br>
  <div class="card">
    <div class="card-header">
      card-header
    </div>
    <div class="card-body">
      card-body
    </div>
  </div>

</div>