Breadcrumb Schema.org Markup RDFA

RDFA

<ol itemscope itemtype="http://schema.org/BreadcrumbList">
  <li itemprop="itemListElement" itemscope
      itemtype="http://schema.org/ListItem">
    <a itemtype="http://schema.org/Thing"
       itemprop="item" href="https://example.com/books">
        <span itemprop="name">Books</span></a>
    <meta itemprop="position" content="1" />
  </li>
  ›
  <li itemprop="itemListElement" itemscope
      itemtype="http://schema.org/ListItem">
    <a itemtype="http://schema.org/Thing"
       itemprop="item" href="https://example.com/books/sciencefiction">
      <span itemprop="name">Science Fiction</span></a>
    <meta itemprop="position" content="2" />
  </li>
  ›
  <li itemprop="itemListElement" itemscope
      itemtype="http://schema.org/ListItem">
    <a itemtype="http://schema.org/Thing"
       itemprop="item" href="https://example.com/books/sciencefiction/awardwinners">
      <span itemprop="name">Award Winners</span></a>
    <meta itemprop="position" content="3" />
  </li>
</ol>
<ol itemscope itemtype="http://schema.org/BreadcrumbList">
  <li itemprop="itemListElement" itemscope
      itemtype="http://schema.org/ListItem">
    <a itemtype="http://schema.org/Thing"
       itemprop="item" href="https://example.com/literature">
      <span itemprop="name">Literature</span></a>
    <meta itemprop="position" content="1" />
  </li>
  ›
  <li itemprop="itemListElement" itemscope
      itemtype="http://schema.org/ListItem">
    <a itemtype="http://schema.org/Thing"
       itemprop="item" href="https://example.com/literature/speculativefiction">
      <span itemprop="name">Speculative Fiction</span></a>
    <meta itemprop="position" content="2" />
  </li>
</ol>

Guida completa: https://www.evemilano.com/breadcrumb-seo/