Squid log format

$hostname %sn %ts.%03tu %tr %>a %Ss/%03Hs %<st %rm %ru %Sh/%<A %mt %{Referer}h %{X-Forwarded-For}h %{User-Agent}h

Field indexes when space-separated:

1. Hostname of the squid
2. Sequence number
3. Seconds (and milliseconds) since epoch
4. Request service time in ms
5. Client IP
6. Squid request status, HTTP status code
7. Reply size including HTTP headers
8. Request method (GET/POST etc)
9. URL
10. Squid hierarchy status, peer IP
11. MIME content type
12. Referer header
13. X-Forwarded-For header
14. User-Agent header