ETags.
--- a/http.rst Fri Nov 12 21:47:05 2010 +0200
+++ b/http.rst Fri Nov 12 21:51:53 2010 +0200
@@ -14,3 +14,23 @@
Content-Encoding: gzip
+* ETags.
+
+Server respond:
+
+ HTTP/1.1 200 OK
+ Last-Modified: Tue, 12 Dec 2006 03:03:59 GMT
+ ETag: "10c24bc-4ab-457e1c1f"
+ Content-Length: 12195
+
+Lately client send:
+
+ GET /i/yahoo.gif HTTP/1.1
+ Host: us.yimg.com
+ If-Modified-Since: Tue, 12 Dec 2006 03:03:59 GMT
+ If-None-Match: "10c24bc-4ab-457e1c1f"
+
+and get respond:
+
+ HTTP/1.1 304 Not Modified
+