Hi alceste
It is not a module position , it is builded from core into this file /templates/gk_instyle/layouts/default.php
<div id="gkTopNav">
<?php if(
$this->API->get('login_url', '') != '' ||
($this->API->get('reg_url', '') != '' && $userID == 0)
) : ?>
<div id="gkUserArea">
<?php echo JText::_('TPL_GK_LANG_USERAREA'); ?>
<?php if($userID == 0) : ?>
<?php echo JText::_('TPL_GK_LANG_USERAREA_VISITOR'); ?>
<?php else : ?>
<strong><?php echo $user->get('username'); ?></strong>
<?php endif; ?>
<?php echo JText::_('TPL_GK_LANG_LOGIN_PRE'); ?>
<?php if($this->API->get('login_url', 'index.php?option=com_users&view=login')) : ?>
<a href="<?php echo $this->API->get('login_url', 'index.php?option=com_users&view=login'); ?>" id="gkLogin"><?php echo ($userID == 0) ? JText::_('TPL_GK_LANG_LOGIN') : JText::_('TPL_GK_LANG_LOGOUT'); ?></a>
<?php endif; ?>
<?php if($this->API->get('reg_url', 'index.php?option=com_users&view=registration') != '' && $userID == 0) : ?>
<?php echo JText::_('TPL_GK_LANG_REGISTER_PRE'); ?>
<a href="<?php echo $this->API->get('reg_url', 'index.php?option=com_users&view=registration'); ?>"><?php echo JText::_('TPL_GK_LANG_REGISTER'); ?></a>
<?php endif; ?>
</div>
<?php endif; ?>
Hope it helps