<em>never</em> has a leading slash. Therefore, a <em>Pattern</em> with <code>^/</code> never
matches in per-directory context.</li>
-<li>Although rewrite rules are syntactically permitted in <code class="directive"><a href="../mod/core.html#location"><Location></a></code> and <code class="directive"><a href="../mod/core.html#files"><Files></a></code> sections, this
-should never be necessary and is unsupported.</li>
+<li>Although rewrite rules are syntactically permitted in <code class="directive"><a href="../mod/core.html#location"><Location></a></code> and <code class="directive"><a href="../mod/core.html#files"><Files></a></code> sections
+(including their regular expression counterparts), this
+should never be necessary and is unsupported. A likely feature
+to break in these contexts is relative substitutions.</li>
</ul>
</div>