I have pages that will be crawled by the google and bing crawlers. One of the pages uses twitter bootstrap 2.3.2 Tabbable nav:
<div class="tabbable">
<ul class="nav nav-tabs">
<li class="active"><a href="#tab1" data-toggle="tab">Section 1</a></li>
<li><a href="#tab2" data-toggle="tab">Section 2</a></li>
</ul>
<div class="tab-content">
<div class="tab-pane active" id="tab1">
<p>I'm in Section 1</p>
</div>
<div class="tab-pane" id="tab2">
<p>Howdy, I'm in Section 2 and not currently visible. Will search engines ignore me?</p>
</div>
</div>
</div>
Since the content on the non active tabs is hidden I could see the search engines applying a significant penalty or discounting that content entirely when they crawl the site--not good news for the tabs since they will need to be removed.
In this link google warns about hiding text. and Matt Cutts says "I don’t recommend that people use CSS to hide text" so clearly you can get penalized for hiding text. However, engines may be smart enough to distinguish valid and invalid hiding.
Is my concern on hidden tabs warranted or do the search engines distinguish?