+<li><tt class="docutils literal"><span class="pre">forward_value</span></tt> - Forward only option's value. Cannot be used with switch
+options (since they don't have values), but works fine with lists.
+Example: <tt class="docutils literal"><span class="pre">(forward_value</span> <span class="pre">"Wa,")</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">forward_transformed_value</span></tt> - As above, but applies a hook to the
+option's value before forwarding (see <a class="reference internal" href="#hooks">below</a>). When
+<tt class="docutils literal"><span class="pre">forward_transformed_value</span></tt> is applied to a list
+option, the hook must have signature
+<tt class="docutils literal"><span class="pre">std::string</span> <span class="pre">hooks::HookName</span> <span class="pre">(const</span> <span class="pre">std::vector<std::string>&)</span></tt>.
+Example: <tt class="docutils literal"><span class="pre">(forward_transformed_value</span> <span class="pre">"m",</span> <span class="pre">"ConvertToMAttr")</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">output_suffix</span></tt> - Modify the output suffix of this tool.