GET /Library/User/ HTTP/1.1
Accept: text/plain,text/html,*/*;q=0.3
Accept-Encoding: deflate
TE: trailers,deflate
Host: www.w3.org
User-Agent: W3CRobot/5.2.3 libwww/5.2.3
Connection: TE,Keep-Alive

HTTP/1.1 200 OK
Date: Wed, 27 Jan 1999 16:30:54 GMT
Server: Apache/1.2.6
Last-Modified: Thu, 17 Dec 1998 01:51:01 GMT
ETag: "3b00c4-c20-36786385"
Content-Length: 3104
Accept-Ranges: bytes
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
Content-Type: text/html; charset=ISO-8859-1

...

GET /Library/User/ HTTP/1.1
Accept: text/plain,text/html,*/*;q=0.3
Accept-Encoding: deflate
TE: trailers,deflate
Host: www.w3.org
If-None-Match: "3b00c4-c20-36786385"
If-Modified-Since: Thu, 17 Dec 1998 00:51:01 GMT
User-Agent: W3CRobot/5.2.3 libwww/5.2.3
Connection: TE,Keep-Alive

HTTP/1.1 304 Not Modified
Date: Wed, 27 Jan 1999 16:31:04 GMT
Server: Apache/1.2.6
Connection: Keep-Alive
Keep-Alive: timeout=15, max=100
ETag: "3b00c4-c20-36786385"