diff --git a/functions/strings.xml b/functions/strings.xml
index 1bd8afb17b..f5f84cc2e0 100644
--- a/functions/strings.xml
+++ b/functions/strings.xml
@@ -144,7 +144,8 @@ $trimmed = chop ($line);
      </para>
     </note>
     <para>
-     See also <function>trim</function>.
+     See also <function>trim</function>, <function>ltrim</function>,
+     <function>rtrim</function>, and <function>chop</function>.
     </para>
    </refsect1>
   </refentry>
@@ -947,7 +948,8 @@ $colon_separated = implode (":", $array);
      and a plain space.
     </para>
     <para>
-     See also <function>chop</function> and <function>trim</function>.
+     See also <function>chop</function>, <function>rtrim</function>, and
+     <function>trim</function>.
     </para>
    </refsect1>
   </refentry>
@@ -1238,7 +1240,8 @@ $trimmed = rtrim ($line);
      </example>
     </para>
     <para>
-     See also <function>trim</function>, <function>ltrim</function>.
+     See also <function>trim</function>, <function>ltrim</function>, and
+     <function>rtrim</function>.
     </para>
    </refsect1>
   </refentry>
@@ -2846,7 +2849,7 @@ echo substr_replace ($var, '', 10, -1) . "&lt;br&gt;\n";
      and a plain space.
     </para>
     <para>
-     See also <function>chop</function> and
+     See also <function>chop</function>, <function>rtrim</function> and
      <function>ltrim</function>.
     </para>
    </refsect1>