+<p>So far, these are the only three miscellaneous option modifiers.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="response">Response files</a>
+</div>
+
+<div class="doc_text">
+
+<p>Some systems, such as certain variants of Microsoft Windows and
+some older Unices have a relatively low limit on command-line
+length. It is therefore customary to use the so-called 'response
+files' to circumvent this restriction. These files are mentioned on
+the command-line (using the "@file") syntax. The program reads these
+files and inserts the contents into argv, thereby working around the
+command-line length limits. Response files are enabled by an optional
+fourth argument to
+<a href="#cl::ParseEnvironmentOptions"><tt>cl::ParseEnvironmentOptions</tt></a>
+and
+<a href="#cl::ParseCommandLineOptions"><tt>cl::ParseCommandLineOptions</tt></a>.
+</p>