My school uses Ironport for filtering/monitoring web traffic. I have a bit of curiosity as to why it tacks on a x-junk: header onto everything. After going through a few curl tests, I've found no real connection between what is shown on the page and the x-junk: header.

here's my curl request: any ideas?

Anchorage:~ khotchkiss$ curl -I google.com
HTTP/1.1 301 Moved Permanently
Location: http://www.google.com/
Content-Type: text/html; charset=UTF-8
Date: Sun, 06 Feb 2011 04:37:25 GMT
Expires: Tue, 08 Mar 2011 04:37:25 GMT
Cache-Control: public, max-age=2592000
Server: gws
X-XSS-Protection: 1; mode=block
Content-Length: 219
Age: 108
Via: 1.1 MC-IRONPORT.UNIVERSITY.LIBERTY.EDU:80 (IronPort-WSA/6.3.3-015)
Connection: keep-alive
X-Junk: xxxxxxxxxxxxxxxxxxxxxxx