diff --git a/inc/themes/classic/searchbox.inc b/inc/themes/classic/searchbox.inc
index 77ca0e98..2293887c 100644
--- a/inc/themes/classic/searchbox.inc
+++ b/inc/themes/classic/searchbox.inc
@@ -4,6 +4,16 @@
             <td id="toolsLeft">
                 <img src="imgs/clear.png" title="<?php echo _('Limpiar'); ?>" class="inputImg" id="btnClear" />
                 <input type="text" name="search" id="txtSearch" value="<?php echo $searchTxt; ?>" placeholder="<?php echo _('Texto a buscar'); ?>"/>
+                <img src="imgs/help.png" title="" class="inputImgMini help-tooltip" />
+                <div class="tooltip" style="display:none;">
+                    <p>
+                        <?php echo _('Parámetros especiales:'); ?>
+                    </p>
+                    <ul>
+                        <li>:user [login] &gt; <?php echo _('Buscar cuentas a las que \'login\' tenga acceso'); ?></li>
+                        <li>:group [group_name] &gt; <?php echo _('Buscar cuentas a las que \'group_name\' tenga acceso'); ?></li>
+                    </ul>
+                </div>
                 <?php if ( $showGlobalSearch && ! $isAdmin ): ?>
                     <label for="chkgsearch" title="<?php echo _('Búsqueda global');?>"><?php echo ($searchGlobal) ? 'ON' : 'OFF'; ?></label>
                     <input type="checkbox" name="chkgsearch" id="chkgsearch" class="checkbox" <?php echo ($searchGlobal) ? 'checked="checked"' : ''; ?>/>
diff --git a/inc/themes/material-blue/searchbox.inc b/inc/themes/material-blue/searchbox.inc
index 31886005..09796892 100644
--- a/inc/themes/material-blue/searchbox.inc
+++ b/inc/themes/material-blue/searchbox.inc
@@ -9,6 +9,16 @@
                            name="search" value="<?php echo $searchTxt; ?>"/>
                     <label class="mdl-textfield__label" for="txtSearch"><?php echo _('Texto a buscar'); ?></label>
                 </div>
+                <div id="help-account_search" class="icon material-icons fg-blue80">help_outline</div>
+                <div class="mdl-tooltip mdl-tooltip--large" for="help-account_search">
+                    <p>
+                        <?php echo _('Parámetros especiales:'); ?>
+                    </p>
+                    <ul>
+                        <li>:user [login] &gt; <?php echo _('Buscar cuentas a las que \'login\' tenga acceso'); ?></li>
+                        <li>:group [group_name] &gt; <?php echo _('Buscar cuentas a las que \'group_name\' tenga acceso'); ?></li>
+                    </ul>
+                </div>
 
                 <?php if ($showGlobalSearch && !$isAdmin): ?>
                     <label class="mdl-switch mdl-js-switch mdl-js-ripple-effect mdl-switch--inline" for="chkgsearch" title="<?php echo _('Búsqueda global'); ?>">