solr/solr-ref-guide/src/_includes/topnav.html

<!-- Navigation -->
<nav id="topnav" class="navbar navbar-expand-md fixed-top bg-light flex-nowrap col-10">
    <div class="container-fluid">
        <div class="navbar-header">
            {% comment %} NOTE: Explicitly using *SOLR* version here (not guide){% endcomment %}
            <img src="images/solr-sunOnly-small.png" width="30" height="30">
            <a class="navbar-brand" href="index.html">
              <span class="projectTitle">Solr {{ site.solr-attributes.solr-docs-version }}</span>
            </a>
        </div>
        <div class="collapse navbar-collapse justify-content-end" id="bs-example-navbar-collapse-1">
            <ul class="nav navbar-nav navbar-right">
                <!-- Link to Solr website -->
                <li><a href="https://solr.apache.org/" target="_blank">Solr Website</a></li>
                <!-- Other Guide Formats dropdown -->
                <li class="dropdown">
                    <a href="#" class="dropdown-toggle" data-toggle="dropdown">Other Formats<b class="caret"></b></a>
                    <ul class="dropdown-menu">
                       <li><a href="https://archive.apache.org/dist/lucene/solr/ref-guide/" target="_blank">Archived PDFs</a></li>
                       <li><a href="https://solr.apache.org/guide/" target="_blank">Other Versions Online</a></li>
                    </ul>
                </li>
                <!-- Solr Resources dropdown -->
                <li class="dropdown">
                    <a href="#" class="dropdown-toggle" data-toggle="dropdown">Solr Resources<b class="caret"></b></a>
                    <ul class="dropdown-menu">
                       <li><a href="{{site.solr-attributes.solr-javadocs}}/solr-core/index.html" target="_blank">Solr Javadocs</a></li>
                       <li><a href="https://solr.apache.org/community.html#version-control" target="_blank">Lucene/Solr Source Code</a></li>
                       <li><a href="https://solr.apache.org/community.html" target="_blank">Solr Community Links</a></li>
                    </ul>
                </li>

            </ul>
        </div>
        </div>
        <!-- /.container -->
</nav>