es of submodules will not be updated.
Just like <a href="git-submodule.html">git-submodule(1)</a>, this will detach <code>HEAD</code> of the
submodule.</p>
</dd>
<dt class="hdlist1">--overlay</dt>
<dt class="hdlist1">--no-overlay</dt>
<dd>
<p>In the default overlay mode, <code>git checkout</code> never
removes files from the index or the working tree.  When
specifying <code>--no-overlay</code>, files that appear in the index and
working tree, but not in <code>&lt;tree-ish&gt;</code> are removed, to make the