If specified, this is the value of the HTTP User-Agent header that SysOrb will send with the request. If you need, for some reason, to send an empty User-Agent header you can achieve this by entering a single space in the input field. If you simply leave the field blank the result will be the same as if you had selected 'Disabled'. The string you specify should conform to the rules of RFC 2616 section 14.43 (http://www.rfc-editor.org/rfc/rfc2616.txt). Examples of valid values are (excluding the citation marks): 'SysOrb', 'Mozilla/5.0 (compatible; Konqueror/3.5; SunOS 5.10; X11; i86pc; en_US) KHTML/3.5.9 (like Gecko)', 'Mozilla/5.0 (X11; U; SunOS i86pc; en-US; rv:18.104.22.168) Gecko/20070622 Firefox/22.214.171.124'.