This function extends the standard CSS oxy_url() function, by allowing you to specify additional relative path components (parameters loc_1 to loc_n). Oxygen XML Author uses all these parameters to construct an absolute location.
url('http://www.oxygenxml.com/css/test.css', '../dir1/', 'dir2/dir3/', '../../dir4/dir5/test.xml')returns
'http://www.oxygenxml.com/dir1/dir4/dir5/test.xml'