Index: /trunk/doc/manual/en_US/user_VBoxManage.xml
===================================================================
--- /trunk/doc/manual/en_US/user_VBoxManage.xml	(revision 71115)
+++ /trunk/doc/manual/en_US/user_VBoxManage.xml	(revision 71116)
@@ -625,4 +625,11 @@
             <para><computeroutput>--longmode on|off</computeroutput>: This
             enables/disables long mode. See <xref linkend="settings-processor" />.</para>
+          </listitem>
+
+          <listitem>
+            <para><computeroutput>--spec-ctrl on|off</computeroutput>: This setting
+            enables/disables exposing speculation control interfaces to the guest, provided
+            they are available on the host. Depending on the host CPU and workload, enabling
+            speculation control may significantly reduce performance.</para>
           </listitem>