IE11 is not?

/frontends/php/include/views/configuration.httpconf.edit.php

// append http agents to form list - http://www.useragentstring.com
$agentComboBox = new CEditableComboBox('agent', $this->data['agent'], ZBX_TEXTBOX_STANDARD_SIZE);
$agentComboBox->addItemsInGroup(_('Internet Explorer'), array(
'Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0)' => 'Internet Explorer 10.0',
'Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US)' => 'Internet Explorer 9.0',
'Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 1.0.3705; .NET CLR 1.1.4322)' => 'Internet Explorer 8.0',
'Mozilla/5.0 (Windows; U; MSIE 7.0; Windows NT 6.0; en-US)' => 'Internet Explorer 7.0',
'Mozilla/5.0 (compatible; MSIE 6.0; Windows NT 5.1)' => 'Internet Explorer 6.0'
));