HTML structure for showing page title as a selected submenu item
<p>On a category archive, I want to use the following layout:</p>

<pre class="lang-none prettyprint-override"><code>CATEGORY NAME

[All] - Subcategory 1 - Subcategory 2 - Subcategory 3

List of all posts from 'CATEGORY NAME'
</code></pre>

<p>with <em>All</em> highlighted. </p>

<p>When somebody clicks on a subcategory, that category highlights and they see posts from that subcategory:</p>

<pre class="lang-none prettyprint-override"><code>CATEGORY NAME

All - [Subcategory 1] - Subcategory 2 - Subcategory 3

List of all posts from 'Subcategory 1'
</code></pre>

<p>It is perfectly clear to users what this means, and that the latter means you are on that subcategory's page.</p>

<p>What is the best way to make this clear to search engines?</p>

<p>As per standard practice, the 'page title' should be an <code>h1</code> tag. For the first case, this is clearly the category name. However, in the latter case it should be the subcategory. Adding an <code>h1</code> inside a navigation list doesn't really make any sense; but keeping the <code>h1</code> tag on the top level category name doesn't really give the right impression.</p>